Question: 71  ON THE WORK OF THE FIFTH DAY (ONE ARTICLE)

   We must next consider the work of the fifth day.

  Objection 1: It would seem that this work is not fittingly described. For the waters produce that which the power of water suffices to produce. But the power of water does not suffice for the production of every kind of fishes and birds since we find that many of them are generated from seed. Therefore the words, "Let the waters bring forth the creeping creature having life, and the fowl that may fly over the earth," do not fittingly describe this work.

  Objection 2: Further, fishes and birds are not produced from water only, but earth seems to predominate over water in their composition, as is shown by the fact that their bodies tend naturally to the earth and rest upon it. It is not, then, fittingly that fishes and birds are produced from water.

  Objection 3: Further, fishes move in the waters, and birds in the air. If, then, fishes are produced from the waters, birds ought to be produced from the air, and not from the waters.

  Objection 4: Further, not all fishes creep through the waters, for some, as seals, have feet and walk on land. Therefore the production of fishes is not sufficiently described by the words, "Let the waters bring forth the creeping creature having life."

  Objection 5: Further, land animals are more perfect than birds and fishes which appears from the fact that they have more distinct limbs, and generation of a higher order. For they bring forth living beings, whereas birds and fishes bring forth eggs. But the more perfect has precedence in the order of nature. Therefore fishes and birds ought not to have been produced on the fifth day, before land animals.

  On the contrary, Suffices the authority of Scripture.

  I answer that, As said above, (Question [70], Article [1]), the order of the work of adornment corresponds to the order of the work of distinction. Hence, as among the three days assigned to the work of distinction, the middle, or second, day is devoted to the work of distinction of water, which is the intermediate body, so in the three days of the work of adornment, the middle day, which is the fifth, is assigned to the adornment of the intermediate body, by the production of birds and fishes. As, then, Moses makes mention of the lights and the light on the fourth day, to show that the fourth day corresponds to the first day on which he had said that the light was made, so on this fifth day he mentions the waters and the firmament of heaven to show that the fifth day corresponds to the second. It must, however, be observed that Augustine differs from other writers in his opinion about the production of fishes and birds, as he differs about the production of plants. For while others say that fishes and birds were produced on the fifth day actually, he holds that the nature of the waters produced them on that day potentially.

  Reply to Objection 1: It was laid down by Avicenna that animals of all kinds can be generated by various minglings of the elements, and naturally, without any kind of seed. This, however, seems repugnant to the fact that nature produces its effects by determinate means, and consequently, those things that are naturally generated from seed cannot be generated naturally in any other way. It ought, then, rather to be said that in the natural generation of all animals that are generated from seed, the active principle lies in the formative power of the seed, but that in the case of animals generated from putrefaction, the formative power of is the influence of the heavenly bodies. The material principle, however, in the generation of either kind of animals, is either some element, or something compounded of the elements. But at the first beginning of the world the active principle was the Word of God, which produced animals from material elements, either in act, as some holy writers say, or virtually, as Augustine teaches. Not as though the power possessed by water or earth of producing all animals resides in the earth and the water themselves, as Avicenna held, but in the power originally given to the elements of producing them from elemental matter by the power of seed or the influence of the stars.

  Reply to Objection 2: The bodies of birds and fishes may be considered from two points of view. If considered in themselves, it will be evident that the earthly element must predominate, since the element that is least active, namely, the earth, must be the most abundant in quantity in order that the mingling may be duly tempered in the body of the animal. But if considered as by nature constituted to move with certain specific motions, thus they have some special affinity with the bodies in which they move; and hence the words in which their generation is described.

  Reply to Objection 3: The air, as not being so apparent to the senses, is not enumerated by itself, but with other things: partly with the water, because the lower region of the air is thickened by watery exhalations; partly with the heaven as to the higher region. But birds move in the lower part of the air, and so are said to fly "beneath the firmament," even if the firmament be taken to mean the region of clouds. Hence the production of birds is ascribed to the water.

  Reply to Objection 4: Nature passes from one extreme to another through the medium; and therefore there are creatures of intermediate type between the animals of the air and those of the water, having something in common with both; and they are reckoned as belonging to that class to which they are most allied, through the characters possessed in common with that class, rather than with the other. But in order to include among fishes all such intermediate forms as have special characters like to theirs, the words, "Let the waters bring forth the creeping creature having life," are followed by these: "God created great whales," etc.

  Reply to Objection 5: The order in which the production of these animals is given has reference to the order of those bodies which they are set to adorn, rather than to the superiority of the animals themselves. Moreover, in generation also the more perfect is reached through the less perfect.

ON THE WORK OF THE SIXTH DAY (ONE ARTICLE)

   We must now consider the work of the sixth day.

  Objection 1: It would seem that this work is not fittingly described. For as birds and fishes have a living soul, so also have land animals. But these animals are not themselves living souls. Therefore the words, "Let the earth bring forth the living creature," should rather have been, "Let the earth bring forth the living four-footed creatures."

  Objection 2: Further, a genus ought not to be opposed to its species. But beasts and cattle are quadrupeds. Therefore quadrupeds ought not to be enumerated as a class with beasts and cattle.

  Objection 3: Further, as animals belong to a determinate genus and species, so also does man. But in the making of man nothing is said of his genus and species, and therefore nothing ought to have been said about them in the production of other animals, whereas it is said "according to its genus" and "in its species."

  Objection 4: Further, land animals are more like man, whom God is recorded to have blessed, than are birds and fishes. But as birds and fishes are said to be blessed, this should have been said, with much more reason, of the other animals as well.

  Objection 5: Further, certain animals are generated from putrefaction, which is a kind of corruption. But corruption is repugnant to the first founding of the world. Therefore such animals should not have been produced at that time.

  Objection 6: Further, certain animals are poisonous, and injurious to man. But there ought to have been nothing injurious to man before man sinned. Therefore such animals ought not to have been made by God at all, since He is the Author of good; or at least not until man had sinned.

  On the contrary, Suffices the authority of Scripture.

  I answer that, As on the fifth day the intermediate body, namely, the water, is adorned, and thus that day corresponds to the second day; so the sixth day, on which the lowest body, or the earth, is adorned by the production of land animals, corresponds to the third day. Hence the earth is mentioned in both places. And here again Augustine says (Gen. ad lit. v) that the production was potential, and other holy writers that it was actual.

  Reply to Objection 1: The different grades of life which are found in different living creatures can be discovered from the various ways in which Scripture speaks of them, as Basil says (Hom. viii in Hexaem.). The life of plants, for instance, is very imperfect and difficult to discern, and hence, in speaking of their production, nothing is said of their life, but only their generation is mentioned, since only in generation is a vital act observed in them. For the powers of nutrition and growth are subordinate to the generative life, as will be shown later on (Question [78], Article [2]). But amongst animals, those that live on land are, generally speaking, more perfect than birds and fishes, not because the fish is devoid of memory, as Basil upholds (Hom. viii in Hexaem.) and Augustine rejects (Gen. ad lit. iii), but because their limbs are more distinct and their generation of a higher order, (yet some imperfect animals, such as bees and ants, are more intelligent in certain ways). Scripture, therefore, does not call fishes "living creatures," but "creeping creatures having life"; whereas it does call land animals "living creatures" on account of their more perfect life, and seems to imply that fishes are merely bodies having in them something of a soul, whilst land animals, from the higher perfection of their life, are, as it were, living souls with bodies subject to them. But the life of man, as being the most perfect grade, is not said to be produced, like the life of other animals, by earth or water, but immediately by God.

  Reply to Objection 2: By "cattle," domestic animals are signified, which in any way are of service to man: but by "beasts," wild animals such as bears and lions are designated. By "creeping things" those animals are meant which either have no feet and cannot rise from the earth, as serpents, or those whose feet are too short to life them far from the ground, as the lizard and tortoise. But since certain animals, as deer and goats, seem to fall under none of these classes, the word "quadrupeds" is added. Or perhaps the word "quadruped" is used first as being the genus, to which the others are added as species, for even some reptiles, such as lizards and tortoises, are four-footed.

  Reply to Objection 3: In other animals, and in plants, mention is made of genus and species, to denote the generation of like from like. But it was unnecessary to do so in the case of man, as what had already been said of other creatures might be understood of him. Again, animals and plants may be said to be produced according to their kinds, to signify their remoteness from the Divine image and likeness, whereas man is said to be made "to the image and likeness of God."

  Reply to Objection 4: The blessing of God gives power to multiply by generation, and, having been mentioned in the preceding account of the making of birds and fishes, could be understood of the beasts of the earth, without requiring to be repeated. The blessing, however, is repeated in the case of man, since in him generation of children has a special relation to the number of the elect [*Cf. Augustine, Gen. ad lit. iii, 12], and to prevent anyone from saying that there was any sin whatever in the act of begetting children. As to plants, since they experience neither desire of propagation, nor sensation in generating, they are deemed unworthy of a formal blessing.

  Reply to Objection 5: Since the generation of one thing is the corruption of another, it was not incompatible with the first formation of things, that from the corruption of the less perfect the more perfect should be generated. Hence animals generated from the corruption of inanimate things, or of plants, may have been generated then. But those generated from corruption of animals could not have been produced then otherwise than potentially.

  Reply to Objection 6: In the words of Augustine (Super. Gen. contr. Manich. i): "If an unskilled person enters the workshop of an artificer he sees in it many appliances of which he does not understand the use, and which, if he is a foolish fellow, he considers unnecessary. Moreover, should he carelessly fall into the fire, or wound himself with a sharp-edged tool, he is under the impression that many of the things there are hurtful; whereas the craftsman, knowing their use, laughs at his folly. And thus some people presume to find fault with many things in this world, through not seeing the reasons for their existence. For though not required for the furnishing of our house, these things are necessary for the perfection of the universe." And, since man before he sinned would have used the things of this world conformably to the order designed, poisonous animals would not have injured him.

Question: 73 ON THE THINGS THAT BELONG TO THE SEVENTH DAY (THREE ARTICLES)

   We must next consider the things that belong to the seventh day. Under this head there are three points of inquiry:

    (1) About the completion of the works;

    (2) About the resting of God;

    (3) About the blessing and sanctifying of this day.

Article: 1 

Whether the completion of the Divine works ought to be ascribed to the seventh day?

  Objection 1: It would seem that the completion of the Divine works ought not to be ascribed to the seventh day. For all things that are done in this world belong to the Divine works. But the consummation of the world will be at the end of the world (Mt. 13:39,40). Moreover, the time of Christ's Incarnation is a time of completion, wherefore it is called "the time of fulness [*Vulg.: 'the fulness of time']" (Gal. 4:4). And Christ Himself, at the moment of His death, cried out, "It is consummated" (Jn. 19:30). Hence the completion of the Divine works does not belong to the seventh day.

  Objection 2: Further, the completion of a work is an act in itself. But we do not read that God acted at all on the seventh day, but rather that He rested from all His work. Therefore the completion of the works does not belong to the seventh day.

  Objection 3: Further, nothing is said to be complete to which many things are added, unless they are merely superfluous, for a thing is called perfect to which nothing is wanting that it ought to possess. But many things were made after the seventh day, as the production of many individual beings, and even of certain new species that are frequently appearing, especially in the case of animals generated from putrefaction. Also, God creates daily new souls. Again, the work of the Incarnation was a new work, of which it is said (Jer. 31:22): "The Lord hath created a new thing upon the earth." Miracles also are new works, of which it is said (Eccles. 36:6): "Renew thy signs, and work new miracles." Moreover, all things will be made new when the Saints are glorified, according to Apoc. 21:5: "And He that sat on the throne said: Behold I make all things new." Therefore the completion of the Divine works ought not to be attributed to the seventh day.

  On the contrary, It is said (Gn. 2:2): "On the seventh day God ended His work which He had made."

  I answer that, The perfection of a thing is twofold, the first perfection and the second perfection. The 'first' perfection is that according to which a thing is substantially perfect, and this perfection is the form of the whole; which form results from the whole having its parts complete. But the 'second' perfection is the end, which is either an operation, as the end of the harpist is to play the harp; or something that is attained by an operation, as the end of the builder is the house that he makes by building. But the first perfection is the cause of the second, because the form is the principle of operation. Now the final perfection, which is the end of the whole universe, is the perfect beatitude of the Saints at the consummation of the world; and the first perfection is the completeness of the universe at its first founding, and this is what is ascribed to the seventh day.

  Reply to Objection 1: The first perfection is the cause of the second, as above said. Now for the attaining of beatitude two things are required, nature and grace. Therefore, as said above, the perfection of beatitude will be at the end of the world. But this consummation existed previously in its causes, as to nature, at the first founding of the world, as to grace, in the Incarnation of Christ. For, "Grace and truth came by Jesus Christ" (Jn. 1:17). So, then, on the seventh day was the consummation of nature, in Christ's Incarnation the consummation of grace, and at the end of the world will be the consummation of glory.

  Reply to Objection 2: God did act on the seventh day, not by creating new creatures, but by directing and moving His creatures to the work proper to them, and thus He made some beginning of the "second" perfection. So that, according to our version of the Scripture, the completion of the works is attributed to the seventh day, though according to another it is assigned to the sixth. Either version, however, may stand, since the completion of the universe as to the completeness of its parts belongs to the sixth day, but its completion as regards their operation, to the seventh. It may also be added that in continuous movement, so long as any movement further is possible, movement cannot be called completed till it comes to rest, for rest denotes consummation of movement. Now God might have made many other creatures besides those which He made in the six days, and hence, by the fact that He ceased making them on the seventh day, He is said on that day to have consummated His work.

  Reply to Objection 3: Nothing entirely new was afterwards made by God, but all things subsequently made had in a sense been made before in the work of the six days. Some things, indeed, had a previous experience materially, as the rib from the side of Adam out of which God formed Eve; whilst others existed not only in matter but also in their causes, as those individual creatures that are now generated existed in the first of their kind. Species, also, that are new, if any such appear, existed beforehand in various active powers; so that animals, and perhaps even new species of animals, are produced by putrefaction by the power which the stars and elements received at the beginning. Again, animals of new kinds arise occasionally from the connection of individuals belonging to different species, as the mule is the offspring of an ass and a mare; but even these existed previously in their causes, in the works of the six days. Some also existed beforehand by way of similitude, as the souls now created. And the work of the Incarnation itself was thus foreshadowed, for as we read (Phil. 2:7), The Son of God "was made in the likeness of men." And again, the glory that is spiritual was anticipated in the angels by way of similitude; and that of the body in the heaven, especially the empyrean. Hence it is written (Eccles. 1:10), "Nothing under the sun is new, for it hath already gone before, in the ages that were before us."
 
Article: 2

Whether God rested on the seventh day from all His work?

  Objection 1: It would seem that God did not rest on the seventh day from all His work. For it is said (Jn. 5:17), "My Father worketh until now, and I work." God, then, did not rest on the seventh day from all His work.

  Objection 2: Further, rest is opposed to movement, or to labor, which movement causes. But, as God produced His work without movement and without labor, He cannot be said to have rested on the seventh day from His work.

  Objection 3: Further, should it be said that God rested on the seventh day by causing man to rest; against this it may be argued that rest is set down in contradistinction to His work; now the words "God created" or "made" this thing or the other cannot be explained to mean that He made man create or make these things. Therefore the resting of God cannot be explained as His making man to rest.

  On the contrary, It is said (Gn. 2:2): "God rested on the seventh day from all the work which He had done."

  I answer that, Rest is, properly speaking, opposed to movement, and consequently to the labor that arises from movement. But although movement, strictly speaking, is a quality of bodies, yet the word is applied also to spiritual things, and in a twofold sense. On the one hand, every operation may be called a movement, and thus the Divine goodness is said to move and go forth to its object, in communicating itself to that object, as Dionysius says (Div. Nom. ii). On the other hand, the desire that tends to an object outside itself, is said to move towards it. Hence rest is taken in two senses, in one sense meaning a cessation from work, in the other, the satisfying of desire. Now, in either sense God is said to have rested on the seventh day. First, because He ceased from creating new creatures on that day, for, as said above (Article [1], ad 3), He made nothing afterwards that had not existed previously, in some degree, in the first works; secondly, because He Himself had no need of the things that He had made, but was happy in the fruition of Himself. Hence, when all things were made He is not said to have rested "in" His works, as though needing them for His own happiness, but to have rested "from" them, as in fact resting in Himself, as He suffices for Himself and fulfils His own desire. And even though from all eternity He rested in Himself, yet the rest in Himself, which He took after He had finished His works, is that rest which belongs to the seventh day. And this, says Augustine, is the meaning of God's resting from His works on that day (Gen. ad lit. iv).

  Reply to Objection 1: God indeed "worketh until now" by preserving and providing for the creatures He has made, but not by the making of new ones.

  Reply to Objection 2: Rest is here not opposed to labor or to movement, but to the production of new creatures, and to the desire tending to an external object.

  Reply to Objection 3: Even as God rests in Himself alone and is happy in the enjoyment of Himself, so our own sole happiness lies in the enjoyment of God. Thus, also, He makes us find rest in Himself, both from His works and our own. It is not, then, unreasonable to say that God rested in giving rest to us. Still, this explanation must not be set down as the only one, and the other is the first and principal explanation.

Article: 3

Whether blessing and sanctifying are due to the seventh day?

  Objection 1: It would seem that blessing and sanctifying are not due to the seventh day. For it is usual to call a time blessed or holy for that some good thing has happened in it, or some evil been avoided. But whether God works or ceases from work nothing accrues to Him or is lost to Him. Therefore no special blessing or sanctifying are due to the seventh day.

  Objection 2: Further, the Latin "benedictio" [blessing] is derived from "bonitas" [goodness]. But it is the nature of good to spread and communicate itself, as Dionysius says (Div. Nom. iv). The days, therefore, in which God produced creatures deserved a blessing rather than the day on which He ceased producing them.

  Objection 3: Further, over each creature a blessing was pronounced, as upon each work it was said, "God saw that it was good." Therefore it was not necessary that after all had been produced, the seventh day should be blessed.

  On the contrary, It is written (Gn. 2:3), "God blessed the seventh day and sanctified it, because in it He had rested from all His work."

  I answer that, As said above (Article [2]), God's rest on the seventh day is understood in two ways. First, in that He ceased from producing new works, though He still preserves and provides for the creatures He has made. Secondly, in that after all His works He rested in Himself. According to the first meaning, then, a blessing befits the seventh day, since, as we explained (Question [72], ad 4), the blessing referred to the increase by multiplication; for which reason God said to the creatures which He blessed: "Increase and multiply." Now, this increase is effected through God's Providence over His creatures, securing the generation of like from like. And according to the second meaning, it is right that the seventh day should have been sanctified, since the special sanctification of every creature consists in resting in God. For this reason things dedicated to God are said to be sanctified.

  Reply to Objection 1: The seventh day is said to be sanctified not because anything can accrue to God, or be taken from Him, but because something is added to creatures by their multiplying, and by their resting in God.

  Reply to Objection 2: In the first six days creatures were produced in their first causes, but after being thus produced, they are multiplied and preserved, and this work also belongs to the Divine goodness. And the perfection of this goodness is made most clear by the knowledge that in it alone God finds His own rest, and we may find ours in its fruition.

  Reply to Objection 3: The good mentioned in the works of each day belongs to the first institution of nature; but the blessing attached to the seventh day, to its propagation.

Question: 74 

ON ALL THE SEVEN DAYS IN COMMON (THREE ARTICLES)

   We next consider all the seven days in common: and there are three points of inquiry:

    (1) As to the sufficiency of these days;

    (2) Whether they are all one day, or more than one?

    (3) As to certain modes of speaking which Scripture uses in narrating the works of the six days.
 
Article: 1 

Whether these days are sufficiently enumerated?

  Objection 1: It would seem that these days are not sufficiently enumerated. For the work of creation is no less distinct from the works of distinction and adornment than these two works are from one another. But separate days are assigned to distinction and to adornment, and therefore separate days should be assigned to creation.

  Objection 2: Further, air and fire are nobler elements than earth and water. But one day is assigned to the distinction of water, and another to the distinction of the land. Therefore, other days ought to be devoted to the distinction of fire and air.

  Objection 3: Further, fish differ from birds as much as birds differ from the beasts of the earth, whereas man differs more from other animals than all animals whatsoever differ from each other. But one day is devoted to the production of fishes, and another to that of the beast of the earth. Another day, then, ought to be assigned to the production of birds and another to that of man.

  Objection 4: Further, it would seem, on the other hand, that some of these days are superfluous. Light, for instance, stands to the luminaries in the relation of accident to subject. But the subject is produced at the same time as the accident proper to it. The light and the luminaries, therefore, ought not to have been produced on different days.

  Objection 5: Further, these days are devoted to the first instituting of the world. But as on the seventh day nothing was instituted, that day ought not to be enumerated with the others.

  I answer that, The reason of the distinction of these days is made clear by what has been said above (Question [70], Article [1]), namely, that the parts of the world had first to be distinguished, and then each part adorned and filled, as it were, by the beings that inhabit it. Now the parts into which the corporeal creation is divided are three, according to some holy writers, these parts being the heaven, or highest part, the water, or middle part, and the earth, or the lowest part. Thus the Pythagoreans teach that perfection consists in three things, the beginning, the middle, and the end. The first part, then, is distinguished on the first day, and adorned on the fourth, the middle part distinguished on the middle day, and adorned on the fifth, and the third part distinguished on the third day, and adorned on the sixth. But Augustine, while agreeing with the above writers as to the last three days, differs as to the first three, for, according to him, spiritual creatures are formed on the first day, and corporeal on the two others, the higher bodies being formed on the first these two days, and the lower on the second. Thus, then, the perfection of the Divine works corresponds to the perfection of the number six, which is the sum of its aliquot parts, one, two, three; since one day is assigned to the forming of spiritual creatures, two to that of corporeal creatures, and three to the work of adornment.

  Reply to Objection 1: According to Augustine, the work of creation belongs to the production of formless matter, and of the formless spiritual nature, both of which are outside of time, as he himself says (Confess. xii, 12). Thus, then, the creation of either is set down before there was any day. But it may also be said, following other holy writers, that the works of distinction and adornment imply certain changes in the creature which are measurable by time; whereas the work of creation lies only in the Divine act producing the substance of beings instantaneously. For this reason, therefore, every work of distinction and adornment is said to take place "in a day," but creation "in the beginning" which denotes something indivisible.

  Reply to Objection 2: Fire and air, as not distinctly known by the unlettered, are not expressly named by Moses among the parts of the world, but reckoned with the intermediate part, or water, especially as regards the lowest part of the air; or with the heaven, to which the higher region of air approaches, as Augustine says (Gen. ad lit. ii, 13).

  Reply to Objection 3: The production of animals is recorded with reference to their adorning the various parts of the world, and therefore the days of their production are separated or united according as the animals adorn the same parts of the world, or different parts.

  Reply to Objection 4: The nature of light, as existing in a subject, was made on the first day; and the making of the luminaries on the fourth day does not mean that their substance was produced anew, but that they then received a form that they had not before, as said above (Question [70], Article [1] ad 2).

  Reply to Objection 5: According to Augustine (Gen. ad lit. iv, 15), after all that has been recorded that is assigned to the six days, something distinct is attributed to the seventh---namely, that on it God rested in Himself from His works: and for this reason it was right that the seventh day should be mentioned after the six. It may also be said, with the other writers, that the world entered on the seventh day upon a new state, in that nothing new was to be added to it, and that therefore the seventh day is mentioned after the six, from its being devoted to cessation from work.
 
Article: 2 

Whether all these days are one day?

  Objection 1: It would seem that all these days are one day. For it is written (Gn. 2:4,5): "These are the generations of the heaven and the earth, when they were created, in the day that the Lord . . . made the heaven and the earth, and every plant of the field, before it sprung up in the earth." Therefore the day in which God made "the heaven and the earth, and every plant of the field," is one and the same day. But He made the heaven and the earth on the first day, or rather before there was any day, but the plant of the field He made on the third day. Therefore the first and third days are but one day, and for a like reason all the rest.

  Objection 2: Further, it is said (Ecclus. 18:1): "He that liveth for ever, created all things together." But this would not be the case if the days of these works were more than one. Therefore they are not many but one only.

  Objection 3: Further, on the seventh day God ceased from all new works. If, then, the seventh day is distinct from the other days, it follows that He did not make that day; which is not admissible.

  Objection 4: Further, the entire work ascribed to one day God perfected in an instant, for with each work are the words (God) "said . . . . and it was . . . done." If, then, He had kept back His next work to another day, it would follow that for the remainder of a day He would have ceased from working and left it vacant, which would be superfluous. The day, therefore, of the preceding work is one with the day of the work that follows.

  On the contrary, It is written (Gn. 1), "The evening and the morning were the second day . . . the third day," and so on. But where there is a second and third there are more than one. There was not, therefore, only one day.

  I answer that, On this question Augustine differs from other expositors. His opinion is that all the days that are called seven, are one day represented in a sevenfold aspect (Gen. ad lit. iv, 22; De Civ. Dei xi, 9; Ad Orosium xxvi); while others consider there were seven distinct days, not one only. Now, these two opinions, taken as explaining the literal text of Genesis, are certainly widely different. For Augustine understands by the word "day," the knowledge in the mind of the angels, and hence, according to him, the first day denotes their knowledge of the first of the Divine works, the second day their knowledge of the second work, and similarly with the rest. Thus, then, each work is said to have been wrought in some one of these days, inasmuch as God wrought in some one of these days, inasmuch as God wrought nothing in the universe without impressing the knowledge thereof on the angelic mind; which can know many things at the same time, especially in the Word, in Whom all angelic knowledge is perfected and terminated. So the distinction of days denotes the natural order of the things known, and not a succession in the knowledge acquired, or in the things produced. Moreover, angelic knowledge is appropriately called "day," since light, the cause of day, is to be found in spiritual things, as Augustine observes (Gen. ad lit. iv, 28). In the opinion of the others, however, the days signify a succession both in time, and in the things produced.

   If, however, these two explanations are looked at as referring to the mode of production, they will be found not greatly to differ, if the diversity of opinion existing on two points, as already shown (Question [67], Article [1]; Question [69], Article [1]), between Augustine and other writers is taken into account. First, because Augustine takes the earth and the water as first created, to signify matter totally without form; but the making of the firmament, the gathering of the waters, and the appearing of dry land, to denote the impression of forms upon corporeal matter. But other holy writers take the earth and the water, as first created, to signify the elements of the universe themselves existing under the proper forms, and the works that follow to mean some sort of distinction in bodies previously existing, as also has been shown (Question [67], Articles [1],4; Question [69], Article [1]). Secondly, some writers hold that plants and animals were produced actually in the work of the six days; Augustine, that they were produced potentially. Now the opinion of Augustine, that the works of the six days were simultaneous, is consistent with either view of the mode of production. For the other writers agree with him that in the first production of things matter existed under the substantial form of the elements, and agree with him also that in the first instituting of the world animals and plants did not exist actually. There remains, however, a difference as to four points; since, according to the latter, there was a time, after the production of creatures, in which light did not exist, the firmament had not been formed, and the earth was still covered by the waters, nor had the heavenly bodies been formed, which is the fourth difference; which are not consistent with Augustine's explanation. In order, therefore, to be impartial, we must meet the arguments of either side.

  Reply to Objection 1: On the day on which God created the heaven and the earth, He created also every plant of the field, not, indeed, actually, but "before it sprung up in the earth," that is, potentially. And this work Augustine ascribes to the third day, but other writers to the first instituting of the world.

  Reply to Objection 2: God created all things together so far as regards their substance in some measure formless. But He did not create all things together, so far as regards that formation of things which lies in distinction and adornment. Hence the word "creation" is significant.

  Reply to Objection 3: On the seventh day God ceased from making new things, but not from providing for their increase, and to this latter work it belongs that the first day is succeeded by other days.

  Reply to Objection 4: All things were not distinguished and adorned together, not from a want of power on God's part, as requiring time in which to work, but that due order might be observed in the instituting of the world. Hence it was fitting that different days should be assigned to the different states of the world, as each succeeding work added to the world a fresh state of perfection.

  Reply to Objection 5: According to Augustine, the order of days refers to the natural order of the works attributed to the days.
 
Article: 3 

Whether Scripture uses suitable words to express the work of the six days?

  Objection 1: It would seem the Scripture does not use suitable words to express the works of the six days. For as light, the firmament, and other similar works were made by the Word of God, so were the heaven and the earth. For "all things were made by Him" (Jn. 1:3). Therefore in the creation of heaven and earth, as in the other works, mention should have been made of the Word of God.

  Objection 2: Further, the water was created by God, yet its creation is not mentioned. Therefore the creation of the world is not sufficiently described.

  Objection 3: Further, it is said (Gn. 1:31): "God saw all the things that He had made, and they were very good." It ought, then, to have been said of each work, "God saw that it was good." The omission, therefore, of these words in the work of creation and in that of the second day, is not fitting.

  Objection 4: Further, the Spirit of God is God Himself. But it does not befit God to move and to occupy place. Therefore the words, "The Spirit of God moved over the waters," are unbecoming.

  Objection 5: Further, what is already made is not made over again. Therefore to the words, "God said: Let the firmament be made . . . and it was so," it is superfluous to add, "God made the firmament." And the like is to be said of other works.

  Objection 6: Further, evening and morning do not sufficiently divide the day, since the day has many parts. Therefore the words, "The evening and morning were the second day" or, "the third day," are not suitable.

  Objection 7: Further, "first," not "one," corresponds to "second" and "third." It should therefore have been said that, "The evening and the morning were the first day," rather than "one day."

  Reply to Objection 1: According to Augustine (Gen. ad lit. i, 4), the person of the Son is mentioned both in the first creation of the world, and in its distinction and adornment, but differently in either place. For distinction and adornment belong to the work by which the world receives its form. But as the giving form to a work of art is by means of the form of the art in the mind of the artist, which may be called his intelligible word, so the giving form to every creature is by the word of God; and for this reason in the works of distinction and adornment the Word is mentioned. But in creation the Son is mentioned as the beginning, by the words, "In the beginning God created," since by creation is understood the production of formless matter. But according to those who hold that the elements were created from the first under their proper forms, another explanation must be given; and therefore Basil says (Hom. ii, iii in Hexaem.) that the words, "God said," signify a Divine command. Such a command, however, could not have been given before creatures had been produced that could obey it.

  Reply to Objection 2: According to Augustine (De Civ. Dei ix, 33), by the heaven is understood the formless spiritual nature, and by the earth, the formless matter of all corporeal things, and thus no creature is omitted. But, according to Basil (Hom. i in Hexaem.), the heaven and the earth, as the two extremes, are alone mentioned, the intervening things being left to be understood, since all these move heavenwards, if light, or earthwards, if heavy. And others say that under the word, "earth," Scripture is accustomed to include all the four elements as (Ps. 148:7,8) after the words, "Praise the Lord from the earth," is added, "fire, hail, snow, and ice."

  Reply to Objection 3: In the account of the creation there is found something to correspond to the words, "God saw that it was good," used in the work of distinction and adornment, and this appears from the consideration that the Holy Spirit is Love. Now, "there are two things," says Augustine (Gen. ad lit. i, 8) which came from God's love of His creatures, their existence and their permanence. That they might then exist, and exist permanently, "the Spirit of God," it is said, "moved over the waters"---that is to say, over that formless matter, signified by water, even as the love of the artist moves over the materials of his art, that out of them he may form his work. And the words, "God saw that it was good," signify that the things that He had made were to endure, since they express a certain satisfaction taken by God in His works, as of an artist in his art: not as though He knew the creature otherwise, or that the creature was pleasing to Him otherwise, than before He made it. Thus in either work, of creation and of formation, the Trinity of Persons is implied. In creation the Person of the Father is indicated by God the Creator, the Person of the Son by the beginning, in which He created, and the Person of the Holy Ghost by the Spirit that moved over the waters. But in the formation, the Person of the Father is indicated by God that speaks, and the Person of the Son by the Word in which He speaks, and the Person of the Holy Spirit by the satisfaction with which God saw that what was made was good. And if the words, "God saw that it was good," are not said of the work of the second day, this is because the work of distinguishing the waters was only begun on that day, but perfected on the third. Hence these words, that are said of the third day, refer also to the second. Or it may be that Scripture does not use these words of approval of the second days' work, because this is concerned with the distinction of things not evident to the senses of mankind. Or, again, because by the firmament is simply understood the cloudy region of the air, which is not one of the permanent parts of the universe, nor of the principal divisions of the world. The above three reasons are given by Rabbi Moses [*Perplex. ii.], and to these may be added a mystical one derived from numbers and assigned by some writers, according to whom the work of the second day is not marked with approval because the second number is an imperfect number, as receding from the perfection of unity.

  Reply to Objection 4: Rabbi Moses (Perplex. ii) understands by the "Spirit of the Lord," the air or the wind, as Plato also did, and says that it is so called according to the custom of Scripture, in which these things are throughout attributed to God. But according to the holy writers, the Spirit of the Lord signifies the Holy Ghost, Who is said to "move over the water"---that is to say, over what Augustine holds to mean formless matter, lest it should be supposed that God loved of necessity the works He was to produce, as though He stood in need of them. For love of that kind is subject to, not superior to, the object of love. Moreover, it is fittingly implied that the Spirit moved over that which was incomplete and unfinished, since that movement is not one of place, but of pre-eminent power, as Augustine says (Gen. ad lit. i, 7). It is the opinion, however, of Basil (Hom. ii in Hexaem.) that the Spirit moved over the element of water, "fostering and quickening its nature and impressing vital power, as the hen broods over her chickens." For water has especially a life-giving power, since many animals are generated in water, and the seed of all animals is liquid. Also the life of the soul is given by the water of baptism, according to Jn. 3:5: "Unless a man be born again of water and the Holy Ghost, he cannot enter into the kingdom of God."

  Reply to Objection 5: According to Augustine (Gen. ad lit. i, 8), these three phrases denote the threefold being of creatures; first, their being in the Word, denoted by the command "Let . . . be made"; secondly, their being in the angelic mind, signified by the words, "It was . . . done"; thirdly, their being in their proper nature, by the words, "He made." And because the formation of the angels is recorded on the first day, it was not necessary there to add, "He made." It may also be said, following other writers, that the words, "He said," and "Let . . . be made," denote God's command, and the words, "It was done," the fulfilment of that command. But as it was necessary, for the sake of those especially who have asserted that all visible things were made by the angels, to mention how things were made, it is added, in order to remove that error, that God Himself made them. Hence, in each work, after the words, "It was done," some act of God is expressed by some such words as, "He made," or, "He divided," or, "He called."

  Reply to Objection 6: According to Augustine (Gen. ad lit. iv, 22,30), by the "evening" and the "morning" are understood the evening and the morning knowledge of the angels, which has been explained (Question [58], Article [6],7). But, according to Basil (Hom. ii in Hexaem.), the entire period takes its name, as is customary, from its more important part, the day. And instance of this is found in the words of Jacob, "The days of my pilgrimage," where night is not mentioned at all. But the evening and the morning are mentioned as being the ends of the day, since day begins with morning and ends with evening, or because evening denotes the beginning of night, and morning the beginning of day. It seems fitting, also, that where the first distinction of creatures is described, divisions of time should be denoted only by what marks their beginning. And the reason for mentioning the evening first is that as the evening ends the day, which begins with the light, the termination of the light at evening precedes the termination of the darkness, which ends with the morning. But Chrysostom's explanation is that thereby it is intended to show that the natural day does not end with the evening, but with the morning (Hom. v in Gen.).

  Reply to Objection 7: The words "one day" are used when day is first instituted, to denote that one day is made up of twenty-four hours. Hence, by mentioning "one," the measure of a natural day is fixed. Another reason may be to signify that a day is completed by the return of the sun to the point from which it commenced its course. And yet another, because at the completion of a week of seven days, the first day returns which is one with the eighth day. The three reasons assigned above are those given by Basil (Hom. ii in Hexaem.).

TREATISE ON MAN (Questions [75]-102)

Question: 75  OF MAN WHO IS COMPOSED OF A SPIRITUAL AND A CORPOREAL SUBSTANCE: AND IN THE FIRST PLACE, CONCERNING WHAT BELONGS TO THE ESSENCE OF THE SOUL (SEVEN ARTICLES)

   Having treated of the spiritual and of the corporeal creature, we now proceed to treat of man, who is composed of a spiritual and corporeal substance. We shall treat first of the nature of man, and secondly of his origin. Now the theologian considers the nature of man in relation to the soul; but not in relation to the body, except in so far as the body has relation to the soul. Hence the first object of our consideration will be the soul. And since Dionysius (Ang. Hier. xi) says that three things are to be found in spiritual substances---essence, power, and operation---we shall treat first of what belongs to the essence of the soul; secondly, of what belongs to its power; thirdly, of what belongs to its operation.

   Concerning the first, two points have to be considered; the first is the nature of the soul considered in itself; the second is the union of the soul with the body. Under the first head there are seven points of inquiry.

    (1) Whether the soul is a body?

    (2) Whether the human soul is a subsistence?

    (3) Whether the souls of brute animals are subsistent?

    (4) Whether the soul is man, or is man composed of soul and body?

    (5) Whether the soul is composed of matter and form?

    (6) Whether the soul is incorruptible?

    (7) Whether the soul is of the same species as an angel?
 
Article: 1 

Whether the soul is a body?

  Objection 1: It would seem that the soul is a body. For the soul is the moving principle of the body. Nor does it move unless moved. First, because seemingly nothing can move unless it is itself moved, since nothing gives what it has not; for instance, what is not hot does not give heat. Secondly, because if there be anything that moves and is not moved, it must be the cause of eternal, unchanging movement, as we find proved Phys. viii, 6; and this does not appear to be the case in the movement of an animal, which is caused by the soul. Therefore the soul is a mover moved. But every mover moved is a body. Therefore the soul is a body.

  Objection 2: Further, all knowledge is caused by means of a likeness. But there can be no likeness of a body to an incorporeal thing. If, therefore, the soul were not a body, it could not have knowledge of corporeal things.

  Objection 3: Further, between the mover and the moved there must be contact. But contact is only between bodies. Since, therefore, the soul moves the body, it seems that the soul must be a body.

  On the contrary, Augustine says (De Trin. vi, 6) that the soul "is simple in comparison with the body, inasmuch as it does not occupy space by its bulk."

  I answer that, To seek the nature of the soul, we must premise that the soul is defined as the first principle of life of those things which live: for we call living things "animate," [*i.e. having a soul], and those things which have no life, "inanimate." Now life is shown principally by two actions, knowledge and movement. The philosophers of old, not being able to rise above their imagination, supposed that the principle of these actions was something corporeal: for they asserted that only bodies were real things; and that what is not corporeal is nothing: hence they maintained that the soul is something corporeal. This opinion can be proved to be false in many ways; but we shall make use of only one proof, based on universal and certain principles, which shows clearly that the soul is not a body.

   It is manifest that not every principle of vital action is a soul, for then the eye would be a soul, as it is a principle of vision; and the same might be applied to the other instruments of the soul: but it is the "first" principle of life, which we call the soul. Now, though a body may be a principle of life, or to be a living thing, as the heart is a principle of life in an animal, yet nothing corporeal can be the first principle of life. For it is clear that to be a principle of life, or to be a living thing, does not belong to a body as such; since, if that were the case, every body would be a living thing, or a principle of life. Therefore a body is competent to be a living thing or even a principle of life, as "such" a body. Now that it is actually such a body, it owes to some principle which is called its act. Therefore the soul, which is the first principle of life, is not a body, but the act of a body; thus heat, which is the principle of calefaction, is not a body, but an act of a body.

  Reply to Objection 1: As everything which is in motion must be moved by something else, a process which cannot be prolonged indefinitely, we must allow that not every mover is moved. For, since to be moved is to pass from potentiality to actuality, the mover gives what it has to the thing moved, inasmuch as it causes it to be in act. But, as is shown in Phys. viii, 6, there is a mover which is altogether immovable, and not moved either essentially, or accidentally; and such a mover can cause an invariable movement. There is, however, another kind of mover, which, though not moved essentially, is moved accidentally; and for this reason it does not cause an invariable movement; such a mover, is the soul. There is, again, another mover, which is moved essentially---namely, the body. And because the philosophers of old believed that nothing existed but bodies, they maintained that every mover is moved; and that the soul is moved directly, and is a body.

  Reply to Objection 2: The likeness of a thing known is not of necessity actually in the nature of the knower; but given a thing which knows potentially, and afterwards knows actually, the likeness of the thing known must be in the nature of the knower, not actually, but only potentially; thus color is not actually in the pupil of the eye, but only potentially. Hence it is necessary, not that the likeness of corporeal things should be actually in the nature of the soul, but that there be a potentiality in the soul for such a likeness. But the ancient philosophers omitted to distinguish between actuality and potentiality; and so they held that the soul must be a body in order to have knowledge of a body; and that it must be composed of the principles of which all bodies are formed in order to know all bodies.

  Reply to Objection 3: There are two kinds of contact; of "quantity," and of "power." By the former a body can be touched only by a body; by the latter a body can be touched by an incorporeal thing, which moves that body.
 
Article: 2 

Whether the human soul is something subsistent?

  Objection 1: It would seem that the human soul is not something subsistent. For that which subsists is said to be "this particular thing." Now "this particular thing" is said not of the soul, but of that which is composed of soul and body. Therefore the soul is not something subsistent.

  Objection 2: Further, everything subsistent operates. But the soul does not operate; for, as the Philosopher says (De Anima i, 4), "to say that the soul feels or understands is like saying that the soul weaves or builds." Therefore the soul is not subsistent.

  Objection 3: Further, if the soul were subsistent, it would have some operation apart from the body. But it has no operation apart from the body, not even that of understanding: for the act of understanding does not take place without a phantasm, which cannot exist apart from the body. Therefore the human soul is not something subsistent.

  On the contrary, Augustine says (De Trin. x, 7): "Who understands that the nature of the soul is that of a substance and not that of a body, will see that those who maintain the corporeal nature of the soul, are led astray through associating with the soul those things without which they are unable to think of any nature---i.e. imaginary pictures of corporeal things." Therefore the nature of the human intellect is not only incorporeal, but it is also a substance, that is, something subsistent.

  I answer that, It must necessarily be allowed that the principle of intellectual operation which we call the soul, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can have knowledge of all corporeal things. Now whatever knows certain things cannot have any of them in its own nature; because that which is in it naturally would impede the knowledge of anything else. Thus we observe that a sick man's tongue being vitiated by a feverish and bitter humor, is insensible to anything sweet, and everything seems bitter to it. Therefore, if the intellectual principle contained the nature of a body it would be unable to know all bodies. Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is likewise impossible for it to understand by means of a bodily organ; since the determinate nature of that organ would impede knowledge of all bodies; as when a certain determinate color is not only in the pupil of the eye, but also in a glass vase, the liquid in the vase seems to be of that same color.

   Therefore the intellectual principle which we call the mind or the intellect has an operation "per se" apart from the body. Now only that which subsists can have an operation "per se." For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent.

  Reply to Objection 1: "This particular thing" can be taken in two senses. Firstly, for anything subsistent; secondly, for that which subsists, and is complete in a specific nature. The former sense excludes the inherence of an accident or of a material form; the latter excludes also the imperfection of the part, so that a hand can be called "this particular thing" in the first sense, but not in the second. Therefore, as the human soul is a part of human nature, it can indeed be called "this particular thing," in the first sense, as being something subsistent; but not in the second, for in this sense, what is composed of body and soul is said to be "this particular thing."

  Reply to Objection 2: Aristotle wrote those words as expressing not his own opinion, but the opinion of those who said that to understand is to be moved, as is clear from the context. Or we may reply that to operate "per se" belongs to what exists "per se." But for a thing to exist "per se," it suffices sometimes that it be not inherent, as an accident or a material form; even though it be part of something. Nevertheless, that is rightly said to subsist "per se," which is neither inherent in the above sense, nor part of anything else. In this sense, the eye or the hand cannot be said to subsist "per se"; nor can it for that reason be said to operate "per se." Hence the operation of the parts is through each part attributed to the whole. For we say that man sees with the eye, and feels with the hand, and not in the same sense as when we say that what is hot gives heat by its heat; for heat, strictly speaking, does not give heat. We may therefore say that the soul understands, as the eye sees; but it is more correct to say that man understands through the soul.

  Reply to Objection 3: The body is necessary for the action of the intellect, not as its origin of action, but on the part of the object; for the phantasm is to the intellect what color is to the sight. Neither does such a dependence on the body prove the intellect to be non-subsistent; otherwise it would follow that an animal is non-subsistent, since it requires external objects of the senses in order to perform its act of perception.
 
Article: 3  

Whether the souls of brute animals are subsistent?

  Objection 1: It would seem that the souls of brute animals are subsistent. For man is of the same 'genus' as other animals; and, as we have just shown (Article [2]), the soul of man is subsistent. Therefore the souls of other animals are subsistent.

  Objection 2: Further, the relation of the sensitive faculty to sensible objects is like the relation of the intellectual faculty to intelligible objects. But the intellect, apart from the body, apprehends intelligible objects. Therefore the sensitive faculty, apart from the body, perceives sensible objects. Therefore, since the souls of brute animals are sensitive, it follows that they are subsistent; just as the human intellectual soul is subsistent.

  Objection 3: Further, the soul of brute animals moves the body. But the body is not a mover, but is moved. Therefore the soul of brute animals has an operation apart from the body.

  On the contrary, Is what is written in the book De Eccl. Dogm. xvi, xvii: "Man alone we believe to have a subsistent soul: whereas the souls of animals are not subsistent."

  I answer that, The ancient philosophers made no distinction between sense and intellect, and referred both a corporeal principle, as has been said (Article [1]). Plato, however, drew a distinction between intellect and sense; yet he referred both to an incorporeal principle, maintaining that sensing, just as understanding, belongs to the soul as such. From this it follows that even the souls of brute animals are subsistent. But Aristotle held that of the operations of the soul, understanding alone is performed without a corporeal organ. On the other hand, sensation and the consequent operations of the sensitive soul are evidently accompanied with change in the body; thus in the act of vision, the pupil of the eye is affected by a reflection of color: and so with the other senses. Hence it is clear that the sensitive soul has no "per se" operation of its own, and that every operation of the sensitive soul belongs to the composite. Wherefore we conclude that as the souls of brute animals have no "per se" operations they are not subsistent. For the operation of anything follows the mode of its being.

  Reply to Objection 1: Although man is of the same "genus" as other animals, he is of a different "species." Specific difference is derived from the difference of form; nor does every difference of form necessarily imply a diversity of "genus."

  Reply to Objection 2: The relation of the sensitive faculty to the sensible object is in one way the same as that of the intellectual faculty to the intelligible object, in so far as each is in potentiality to its object. But in another way their relations differ, inasmuch as the impression of the object on the sense is accompanied with change in the body; so that excessive strength of the sensible corrupts sense; a thing that never occurs in the case of the intellect. For an intellect that understands the highest of intelligible objects is more able afterwards to understand those that are lower. If, however, in the process of intellectual operation the body is weary, this result is accidental, inasmuch as the intellect requires the operation of the sensitive powers in the production of the phantasms.

  Reply to Objection 3: Motive power is of two kinds. One, the appetitive power, commands motion. The operation of this power in the sensitive soul is not apart from the body; for anger, joy, and passions of a like nature are accompanied by a change in the body. The other motive power is that which executes motion in adapting the members for obeying the appetite; and the act of this power does not consist in moving, but in being moved. Whence it is clear that to move is not an act of the sensitive soul without the body.

Article: 4 

Whether the soul is man?

  Objection 1: It would seem that the soul is man. For it is written (2 Cor. 4:16): "Though our outward man is corrupted, yet the inward man is renewed day by day." But that which is within man is the soul. Therefore the soul is the inward man.

  Objection 2: Further, the human soul is a substance. But it is not a universal substance. Therefore it is a particular substance. Therefore it is a "hypostasis" or a person; and it can only be a human person. Therefore the soul is man; for a human person is a man.

  On the contrary, Augustine (De Civ. Dei xix, 3) commends Varro as holding "that man is not a mere soul, nor a mere body; but both soul and body."

  I answer that, The assertion "the soul is man," can be taken in two senses. First, that man is a soul; though this particular man, Socrates, for instance, is not a soul, but composed of soul and body. I say this, forasmuch as some held that the form alone belongs to the species; while matter is part of the individual, and not the species. This cannot be true; for to the nature of the species belongs what the definition signifies; and in natural things the definition does not signify the form only, but the form and the matter. Hence in natural things the matter is part of the species; not, indeed, signate matter, which is the principle of individuality; but the common matter. For as it belongs to the notion of this particular man to be composed of this soul, of this flesh, and of these bones; so it belongs to the notion of man to be composed of soul, flesh, and bones; for whatever belongs in common to the substance of all the individuals contained under a given species, must belong to the substance of the species.

   It may also be understood in this sense, that this soul is this man; and this could be held if it were supposed that the operation of the sensitive soul were proper to it, apart from the body; because in that case all the operations which are attributed to man would belong to the soul only; and whatever performs the operations proper to a thing, is that thing; wherefore that which performs the operations of a man is man. But it has been shown above (Article [3]) that sensation is not the operation of the soul only. Since, then, sensation is an operation of man, but not proper to him, it is clear that man is not a soul only, but something composed of soul and body. Plato, through supposing that sensation was proper to the soul, could maintain man to be a soul making use of the body.

  Reply to Objection 1: According to the Philosopher (Ethic. ix, 8), a thing seems to be chiefly what is principle in it; thus what the governor of a state does, the state is said to do. In this way sometimes what is principle in man is said to be man; sometimes, indeed, the intellectual part which, in accordance with truth, is called the "inward" man; and sometimes the sensitive part with the body is called man in the opinion of those whose observation does not go beyond the senses. And this is called the "outward" man.

  Reply to Objection 2: Not every particular substance is a hypostasis or a person, but that which has the complete nature of its species. Hence a hand, or a foot, is not called a hypostasis, or a person; nor, likewise, is the soul alone so called, since it is a part of the human species.
 
Article: 5 

Whether the soul is composed of matter and form?

  Objection 1: It would seem that the soul is composed of matter and form. For potentiality is opposed to actuality. Now, whatsoever things are in actuality participate of the First Act, which is God; by participation of Whom, all things are good, are beings, and are living things, as is clear from the teaching of Dionysius (Div. Nom. v). Therefore whatsoever things are in potentiality participate of the first potentiality. But the first potentiality is primary matter. Therefore, since the human soul is, after a manner, in potentiality; which appears from the fact that sometimes a man is potentially understanding; it seems that the human soul must participate of primary matter, as part of itself.

  Objection 2: Further, wherever the properties of matter are found, there matter is. But the properties of matter are found in the soul---namely, to be a subject, and to be changed, for it is a subject to science, and virtue; and it changes from ignorance to knowledge and from vice to virtue. Therefore matter is in the soul.

  Objection 3: Further, things which have no matter, have no cause of their existence, as the Philosopher says Metaph. viii (Did. vii, 6). But the soul has a cause of its existence, since it is created by God. Therefore the soul has matter.

  Objection 4: Further, what has no matter, and is a form only, is a pure act, and is infinite. But this belongs to God alone. Therefore the soul has matter.

  On the contrary, Augustine (Gen. ad lit. vii, 7,8,9) proves that the soul was made neither of corporeal matter, nor of spiritual matter.

  I answer that, The soul has no matter. We may consider this question in two ways. First, from the notion of a soul in general; for it belongs to the notion of a soul to be the form of a body. Now, either it is a form by virtue of itself, in its entirety, or by virtue of some part of itself. If by virtue of itself in its entirety, then it is impossible that any part of it should be matter, if by matter we understand something purely potential: for a form, as such, is an act; and that which is purely potentiality cannot be part of an act, since potentiality is repugnant to actuality as being opposite thereto. If, however, it be a form by virtue of a part of itself, then we call that part the soul: and that matter, which it actualizes first, we call the "primary animate."

   Secondly, we may proceed from the specific notion of the human soul inasmuch as it is intellectual. For it is clear that whatever is received into something is received according to the condition of the recipient. Now a thing is known in as far as its form is in the knower. But the intellectual soul knows a thing in its nature absolutely: for instance, it knows a stone absolutely as a stone; and therefore the form of a stone absolutely, as to its proper formal idea, is in the intellectual soul. Therefore the intellectual soul itself is an absolute form, and not something composed of matter and form. For if the intellectual soul were composed of matter and form, the forms of things would be received into it as individuals, and so it would only know the individual: just as it happens with the sensitive powers which receive forms in a corporeal organ; since matter is the principle by which forms are individualized. It follows, therefore, that the intellectual soul, and every intellectual substance which has knowledge of forms absolutely, is exempt from composition of matter and form.

  Reply to Objection 1: The First Act is the universal principle of all acts; because It is infinite, virtually "precontaining all things," as Dionysius says (Div. Nom. v). Wherefore things participate of It not as a part of themselves, but by diffusion of Its processions. Now as potentiality is receptive of act, it must be proportionate to act. But the acts received which proceed from the First Infinite Act, and are participations thereof, are diverse, so that there cannot be one potentiality which receives all acts, as there is one act, from which all participated acts are derived; for then the receptive potentiality would equal the active potentiality of the First Act. Now the receptive potentiality in the intellectual soul is other than the receptive potentiality of first matter, as appears from the diversity of the things received by each. For primary matter receives individual forms; whereas the intelligence receives absolute forms. Hence the existence of such a potentiality in the intellectual soul does not prove that the soul is composed of matter and form.

  Reply to Objection 2: To be a subject and to be changed belong to matter by reason of its being in potentiality. As, therefore, the potentiality of the intelligence is one thing and the potentiality of primary matter another, so in each is there a different reason of subjection and change. For the intelligence is subject to knowledge, and is changed from ignorance to knowledge, by reason of its being in potentiality with regard to the intelligible species.

  Reply to Objection 3: The form causes matter to be, and so does the agent; wherefore the agent causes matter to be, so far as it actualizes it by transmuting it to the act of a form. A subsistent form, however, does not owe its existence to some formal principle, nor has it a cause transmuting it from potentiality to act. So after the words quoted above, the Philosopher concludes, that in things composed of matter and form "there is no other cause but that which moves from potentiality to act; while whatsoever things have no matter are simply beings at once." [*The Leonine edition has, "simpliciter sunt quod vere entia aliquid." The Parma edition of St. Thomas's Commentary on Aristotle has, "statim per se unum quiddam est . . . et ens quiddam."]

  Reply to Objection 4: Everything participated is compared to the participator as its act. But whatever created form be supposed to subsist "per se," must have existence by participation; for "even life," or anything of that sort, "is a participator of existence," as Dionysius says (Div. Nom. v). Now participated existence is limited by the capacity of the participator; so that God alone, Who is His own existence, is pure act and infinite. But in intellectual substances there is composition of actuality and potentiality, not, indeed, of matter and form, but of form and participated existence. Wherefore some say that they are composed of that "whereby they are" and that "which they are"; for existence itself is that by which a thing is.
 
Article: 6 

Whether the human soul is incorruptible?

  Objection 1: It would seem that the human soul is corruptible. For those things that have a like beginning and process seemingly have a like end. But the beginning, by generation, of men is like that of animals, for they are made from the earth. And the process of life is alike in both; because "all things breathe alike, and man hath nothing more than the beast," as it is written (Eccles. 3:19). Therefore, as the same text concludes, "the death of man and beast is one, and the condition of both is equal." But the souls of brute animals are corruptible. Therefore, also, the human soul is corruptible.

  Objection 2: Further, whatever is out of nothing can return to nothingness; because the end should correspond to the beginning. But as it is written (Wis. 2:2), "We are born of nothing"; which is true, not only of the body, but also of the soul. Therefore, as is concluded in the same passage, "After this we shall be as if we had not been," even as to our soul.

  Objection 3: Further, nothing is without its own proper operation. But the operation proper to the soul, which is to understand through a phantasm, cannot be without the body. For the soul understands nothing without a phantasm; and there is no phantasm without the body as the Philosopher says (De Anima i, 1). Therefore the soul cannot survive the dissolution of the body.

  On the contrary, Dionysius says (Div. Nom. iv) that human souls owe to Divine goodness that they are "intellectual," and that they have "an incorruptible substantial life."

  I answer that, We must assert that the intellectual principle which we call the human soul is incorruptible. For a thing may be corrupted in two ways---"per se," and accidentally. Now it is impossible for any substance to be generated or corrupted accidentally, that is, by the generation or corruption of something else. For generation and corruption belong to a thing, just as existence belongs to it, which is acquired by generation and lost by corruption. Therefore, whatever has existence "per se" cannot be generated or corrupted except 'per se'; while things which do not subsist, such as accidents and material forms, acquire existence or lost it through the generation or corruption of composite things. Now it was shown above (Articles [2],3) that the souls of brutes are not self-subsistent, whereas the human soul is; so that the souls of brutes are corrupted, when their bodies are corrupted; while the human soul could not be corrupted unless it were corrupted "per se." This, indeed, is impossible, not only as regards the human soul, but also as regards anything subsistent that is a form alone. For it is clear that what belongs to a thing by virtue of itself is inseparable from it; but existence belongs to a form, which is an act, by virtue of itself. Wherefore matter acquires actual existence as it acquires the form; while it is corrupted so far as the form is separated from it. But it is impossible for a form to be separated from itself; and therefore it is impossible for a subsistent form to cease to exist.

   Granted even that the soul is composed of matter and form, as some pretend, we should nevertheless have to maintain that it is incorruptible. For corruption is found only where there is contrariety; since generation and corruption are from contraries and into contraries. Wherefore the heavenly bodies, since they have no matter subject to contrariety, are incorruptible. Now there can be no contrariety in the intellectual soul; for it receives according to the manner of its existence, and those things which it receives are without contrariety; for the notions even of contraries are not themselves contrary, since contraries belong to the same knowledge. Therefore it is impossible for the intellectual soul to be corruptible. Moreover we may take a sign of this from the fact that everything naturally aspires to existence after its own manner. Now, in things that have knowledge, desire ensues upon knowledge. The senses indeed do not know existence, except under the conditions of "here" and "now," whereas the intellect apprehends existence absolutely, and for all time; so that everything that has an intellect naturally desires always to exist. But a natural desire cannot be in vain. Therefore every intellectual substance is incorruptible.

  Reply to Objection 1: Solomon reasons thus in the person of the foolish, as expressed in the words of Wisdom 2. Therefore the saying that man and animals have a like beginning in generation is true of the body; for all animals alike are made of earth. But it is not true of the soul. For the souls of brutes are produced by some power of the body; whereas the human soul is produced by God. To signify this it is written as to other animals: "Let the earth bring forth the living soul" (Gn. 1:24): while of man it is written (Gn. 2:7) that "He breathed into his face the breath of life." And so in the last chapter of Ecclesiastes (12:7) it is concluded: "(Before) the dust return into its earth from whence it was; and the spirit return to God Who gave it." Again the process of life is alike as to the body, concerning which it is written (Eccles. 3:19): "All things breathe alike," and (Wis. 2:2), "The breath in our nostrils is smoke." But the process is not alike of the soul; for man is intelligent, whereas animals are not. Hence it is false to say: "Man has nothing more than beasts." Thus death comes to both alike as to the body, by not as to the soul.

  Reply to Objection 2: As a thing can be created by reason, not of a passive potentiality, but only of the active potentiality of the Creator, Who can produce something out of nothing, so when we say that a thing can be reduced to nothing, we do not imply in the creature a potentiality to non-existence, but in the Creator the power of ceasing to sustain existence. But a thing is said to be corruptible because there is in it a potentiality to non-existence.

  Reply to Objection 3: To understand through a phantasm is the proper operation of the soul by virtue of its union with the body. After separation from the body it will have another mode of understanding, similar to other substances separated from bodies, as will appear later on (Question [89], Article [1]).

Article: 7 

Whether the soul is of the same species as an angel?

  Objection 1: It would seem that the soul is of the same species as an angel. For each thing is ordained to its proper end by the nature of its species, whence is derived its inclination for that end. But the end of the soul is the same as that of an angel---namely, eternal happiness. Therefore they are of the same species.

  Objection 2: Further, the ultimate specific difference is the noblest, because it completes the nature of the species. But there is nothing nobler either in an angel or in the soul than their intellectual nature. Therefore the soul and the angel agree in the ultimate specific difference: therefore they belong to the same species.

  Objection 3: Further, it seems that the soul does not differ from an angel except in its union with the body. But as the body is outside the essence of the soul, it seems that it does not belong to its species. Therefore the soul and angel are of the same species.

  On the contrary, Things which have different natural operations are of different species. But the natural operations of the soul and of an angel are different; since, as Dionysius says (Div. Nom. vii), "Angelic minds have simple and blessed intelligence, not gathering their knowledge of Divine things from visible things." Subsequently he says the contrary to this of the soul. Therefore the soul and an angel are not of the same species.

  I answer that, Origen (Peri Archon iii, 5) held that human souls and angels are all of the same species; and this because he supposed that in these substances the difference of degree was accidental, as resulting from their free-will: as we have seen above (Question [47], Article [2]). But this cannot be; for in incorporeal substances there cannot be diversity of number without diversity of species and inequality of nature; because, as they are not composed of matter and form, but are subsistent forms, it is clear that there is necessarily among them a diversity of species. For a separate form cannot be understood otherwise than as one of a single species; thus, supposing a separate whiteness to exist, it could only be one; forasmuch as one whiteness does not differ from another except as in this or that subject. But diversity of species is always accompanied with a diversity of nature; thus in species of colors one is more perfect than another; and the same applies to other species, because differences which divide a "genus" are contrary to one another. Contraries, however, are compared to one another as the perfect to the imperfect, since the "principle of contrariety is habit, and privation thereof," as is written Metaph. x (Did. ix, 4). The same would follow if the aforesaid substances were composed of matter and form. For if the matter of one be distinct from the matter of another, it follows that either the form is the principle of the distinction of matter---that is to say, that the matter is distinct on account of its relation to divers forms; and even then there would result a difference of species and inequality of nature: or else the matter is the principle of the distinction of forms. But one matter cannot be distinct from another, except by a distinction of quantity, which has no place in these incorporeal substances, such as an angel and the soul. So that it is not possible for the angel and the soul to be of the same species. How it is that there can be many souls of one species will be explained later (Question [76], Article [2], ad 1).

  Reply to Objection 1: This argument proceeds from the proximate and natural end. Eternal happiness is the ultimate and supernatural end.

  Reply to Objection 2: The ultimate specific difference is the noblest because it is the most determinate, in the same way as actuality is nobler than potentiality. Thus, however, the intellectual faculty is not the noblest, because it is indeterminate and common to many degrees of intellectuality; as the sensible faculty is common to many degrees in the sensible nature. Hence, as all sensible things are not of one species, so neither are all intellectual things of one species.

  Reply to Objection 3: The body is not of the essence of the soul; but the soul by the nature of its essence can be united to the body, so that, properly speaking, not the soul alone, but the "composite," is the species. And the very fact that the soul in a certain way requires the body for its operation, proves that the soul is endowed with a grade of intellectuality inferior to that of an angel, who is not united to a body.

Question: 76 OF THE UNION OF BODY AND SOUL (EIGHT ARTICLES)

   We now consider the union of the soul with the body; and concerning this there are eight points of inquiry:

    (1) Whether the intellectual principle is united to the body as its form?

    (2) Whether the intellectual principle is multiplied numerically according to the number of bodies; or is there one intelligence for all men?

    (3) Whether in the body the form of which is an intellectual principle, there is some other soul?

    (4) Whether in the body there is any other substantial form?

    (5) Of the qualities required in the body of which the intellectual principle is the form?

    (6) Whether it be united to such a body by means of another body?

    (7) Whether by means of an accident?

    (8) Whether the soul is wholly in each part of the body?

Article: 1 

Whether the intellectual principle is united to the body as its form?

  Objection 1: It seems that the intellectual principle is not united to the body as its form. For the Philosopher says (De Anima iii, 4) that the intellect is "separate," and that it is not the act of any body. Therefore it is not united to the body as its form.

  Objection 2: Further, every form is determined according to the nature of the matter of which it is the form; otherwise no proportion would be required between matter and form. Therefore if the intellect were united to the body as its form, since every body has a determinate nature, it would follow that the intellect has a determinate nature; and thus, it would not be capable of knowing all things, as is clear from what has been said (Question [75], Article [2]); which is contrary to the nature of the intellect. Therefore the intellect is not united to the body as its form.

  Objection 3: Further, whatever receptive power is an act of a body, receives a form materially and individually; for what is received must be received according to the condition of the receiver. But the form of the thing understood is not received into the intellect materially and individually, but rather immaterially and universally: otherwise the intellect would not be capable of the knowledge of immaterial and universal objects, but only of individuals, like the senses. Therefore the intellect is not united to the body as its form.

  Objection 4: Further, power and action have the same subject; for the same subject is what can, and does, act. But the intellectual action is not the action of a body, as appears from above (Question [75], Article [2]). Therefore neither is the intellectual faculty a power of the body. But virtue or power cannot be more abstract or more simple than the essence from which the faculty or power is derived. Therefore neither is the substance of the intellect the form of a body.

  Objection 5: Further, whatever has "per se" existence is not united to the body as its form; because a form is that by which a thing exists: so that the very existence of a form does not belong to the form by itself. But the intellectual principle has "per se" existence and is subsistent, as was said above (Question [75], Article [2]). Therefore it is not united to the body as its form.

  Objection 6: Further, whatever exists in a thing by reason of its nature exists in it always. But to be united to matter belongs to the form by reason of its nature; because form is the act of matter, not by an accidental quality, but by its own essence; otherwise matter and form would not make a thing substantially one, but only accidentally one. Therefore a form cannot be without its own proper matter. But the intellectual principle, since it is incorruptible, as was shown above (Question [75], Article [6]), remains separate from the body, after the dissolution of the body. Therefore the intellectual principle is not united to the body as its form.

  On the contrary, According to the Philosopher, Metaph. viii (Did. vii 2), difference is derived from the form. But the difference which constitutes man is "rational," which is applied to man on account of his intellectual principle. Therefore the intellectual principle is the form of man.

  I answer that, We must assert that the intellect which is the principle of intellectual operation is the form of the human body. For that whereby primarily anything acts is a form of the thing to which the act is to be attributed: for instance, that whereby a body is primarily healed is health, and that whereby the soul knows primarily is knowledge; hence health is a form of the body, and knowledge is a form of the soul. The reason is because nothing acts except so far as it is in act; wherefore a thing acts by that whereby it is in act. Now it is clear that the first thing by which the body lives is the soul. And as life appears through various operations in different degrees of living things, that whereby we primarily perform each of all these vital actions is the soul. For the soul is the primary principle of our nourishment, sensation, and local movement; and likewise of our understanding. Therefore this principle by which we primarily understand, whether it be called the intellect or the intellectual soul, is the form of the body. This is the demonstration used by Aristotle (De Anima ii, 2).

   But if anyone says that the intellectual soul is not the form of the body he must first explain how it is that this action of understanding is the action of this particular man; for each one is conscious that it is himself who understands. Now an action may be attributed to anyone in three ways, as is clear from the Philosopher (Phys. v, 1); for a thing is said to move or act, either by virtue of its whole self, for instance, as a physician heals; or by virtue of a part, as a man sees by his eye; or through an accidental quality, as when we say that something that is white builds, because it is accidental to the builder to be white. So when we say that Socrates or Plato understands, it is clear that this is not attributed to him accidentally; since it is ascribed to him as man, which is predicated of him essentially. We must therefore say either that Socrates understands by virtue of his whole self, as Plato maintained, holding that man is an intellectual soul; or that intelligence is a part of Socrates. The first cannot stand, as was shown above (Question [75], Article [4]), for this reason, that it is one and the same man who is conscious both that he understands, and that he senses. But one cannot sense without a body: therefore the body must be some part of man. It follows therefore that the intellect by which Socrates understands is a part of Socrates, so that in some way it is united to the body of Socrates.

   The Commentator held that this union is through the intelligible species, as having a double subject, in the possible intellect, and in the phantasms which are in the corporeal organs. Thus through the intelligible species the possible intellect is linked to the body of this or that particular man. But this link or union does not sufficiently explain the fact, that the act of the intellect is the act of Socrates. This can be clearly seen from comparison with the sensitive faculty, from which Aristotle proceeds to consider things relating to the intellect. For the relation of phantasms to the intellect is like the relation of colors to the sense of sight, as he says De Anima iii, 5,7. Therefore, as the species of colors are in the sight, so are the species of phantasms in the possible intellect. Now it is clear that because the colors, the images of which are in the sight, are on a wall, the action of seeing is not attributed to the wall: for we do not say that the wall sees, but rather that it is seen. Therefore, from the fact that the species of phantasms are in the possible intellect, it does not follow that Socrates, in whom are the phantasms, understands, but that he or his phantasms are understood.

   Some, however, tried to maintain that the intellect is united to the body as its motor; and hence that the intellect and body form one thing so that the act of the intellect could be attributed to the whole. This is, however, absurd for many reasons. First, because the intellect does not move the body except through the appetite, the movement of which presupposes the operation of the intellect. The reason therefore why Socrates understands is not because he is moved by his intellect, but rather, contrariwise, he is moved by his intellect because he understands. Secondly, because since Socrates is an individual in a nature of one essence composed of matter and form, if the intellect be not the form, it follows that it must be outside the essence, and then the intellect is the whole Socrates as a motor to the thing moved. Whereas the act of intellect remains in the agent, and does not pass into something else, as does the action of heating. Therefore the action of understanding cannot be attributed to Socrates for the reason that he is moved by his intellect. Thirdly, because the action of a motor is never attributed to the thing moved, except as to an instrument; as the action of a carpenter to a saw. Therefore if understanding is attributed to Socrates, as the action of what moves him, it follows that it is attributed to him as to an instrument. This is contrary to the teaching of the Philosopher, who holds that understanding is not possible through a corporeal instrument (De Anima iii, 4). Fourthly, because, although the action of a part be attributed to the whole, as the action of the eye is attributed to a man; yet it is never attributed to another part, except perhaps indirectly; for we do not say that the hand sees because the eye sees. Therefore if the intellect and Socrates are united in the above manner, the action of the intellect cannot be attributed to Socrates. If, however, Socrates be a whole composed of a union of the intellect with whatever else belongs to Socrates, and still the intellect be united to those other things only as a motor, it follows that Socrates is not one absolutely, and consequently neither a being absolutely, for a thing is a being according as it is one.

   There remains, therefore, no other explanation than that given by Aristotle---namely, that this particular man understands, because the intellectual principle is his form. Thus from the very operation of the intellect it is made clear that the intellectual principle is united to the body as its form.

   The same can be clearly shown from the nature of the human species. For the nature of each thing is shown by its operation. Now the proper operation of man as man is to understand; because he thereby surpasses all other animals. Whence Aristotle concludes (Ethic. x, 7) that the ultimate happiness of man must consist in this operation as properly belonging to him. Man must therefore derive his species from that which is the principle of this operation. But the species of anything is derived from its form. It follows therefore that the intellectual principle is the proper form of man.

   But we must observe that the nobler a form is, the more it rises above corporeal matter, the less it is merged in matter, and the more it excels matter by its power and its operation; hence we find that the form of a mixed body has another operation not caused by its elemental qualities. And the higher we advance in the nobility of forms, the more we find that the power of the form excels the elementary matter; as the vegetative soul excels the form of the metal, and the sensitive soul excels the vegetative soul. Now the human soul is the highest and noblest of forms. Wherefore it excels corporeal matter in its power by the fact that it has an operation and a power in which corporeal matter has no share whatever. This power is called the intellect.

   It is well to remark that if anyone holds that the soul is composed of matter and form, it would follow that in no way could the soul be the form of the body. For since the form is an act, and matter is only in potentiality, that which is composed of matter and form cannot be the form of another by virtue of itself as a whole. But if it is a form by virtue of some part of itself, then that part which is the form we call the soul, and that of which it is the form we call the "primary animate," as was said above (Question [75], Article [5]).

  Reply to Objection 1: As the Philosopher says (Phys. ii, 2), the ultimate natural form to which the consideration of the natural philosopher is directed is indeed separate; yet it exists in matter. He proves this from the fact that "man and the sun generate man from matter." It is separate indeed according to its intellectual power, because the intellectual power does not belong to a corporeal organ, as the power of seeing is the act of the eye; for understanding is an act which cannot be performed by a corporeal organ, like the act of seeing. But it exists in matter so far as the soul itself, to which this power belongs, is the form of the body, and the term of human generation. And so the Philosopher says (De Anima iii) that the intellect is separate, because it is not the faculty of a corporeal organ.

   From this it is clear how to answer the Second and Third objections: since, in order that man may be able to understand all things by means of his intellect, and that his intellect may understand immaterial things and universals, it is sufficient that the intellectual power be not the act of the body.

  Reply to Objection 4: The human soul, by reason of its perfection, is not a form merged in matter, or entirely embraced by matter. Therefore there is nothing to prevent some power thereof not being the act of the body, although the soul is essentially the form of the body.

  Reply to Objection 5: The soul communicates that existence in which it subsists to the corporeal matter, out of which and the intellectual soul there results unity of existence; so that the existence of the whole composite is also the existence of the soul. This is not the case with other non-subsistent forms. For this reason the human soul retains its own existence after the dissolution of the body; whereas it is not so with other forms.

  Reply to Objection 6: To be united to the body belongs to the soul by reason of itself, as it belongs to a light body by reason of itself to be raised up. And as a light body remains light, when removed from its proper place, retaining meanwhile an aptitude and an inclination for its proper place; so the human soul retains its proper existence when separated from the body, having an aptitude and a natural inclination to be united to the body.
 
Article: 2 

Whether the intellectual principle is multiplied according to the number of bodies?

  Objection 1: It would seem that the intellectual principle is not multiplied according to the number of bodies, but that there is one intellect in all men. For an immaterial substance is not multiplied in number within one species. But the human soul is an immaterial substance; since it is not composed of matter and form as was shown above (Question [75], Article [5]). Therefore there are not many human souls in one species. But all men are of one species. Therefore there is but one intellect in all men.

  Objection 2: Further, when the cause is removed, the effect is also removed. Therefore, if human souls were multiplied according to the number of bodies, it follows that the bodies being removed, the number of souls would not remain; but from all the souls there would be but a single remainder. This is heretical; for it would do away with the distinction of rewards and punishments.

  Objection 3: Further, if my intellect is distinct from your intellect, my intellect is an individual, and so is yours; for individuals are things which differ in number but agree in one species. Now whatever is received into anything must be received according to the condition of the receiver. Therefore the species of things would be received individually into my intellect, and also into yours: which is contrary to the nature of the intellect which knows universals.

  Objection 4: Further, the thing understood is in the intellect which understands. If, therefore, my intellect is distinct from yours, what is understood by me must be distinct from what is understood by you; and consequently it will be reckoned as something individual, and be only potentially something understood; so that the common intention will have to be abstracted from both; since from things diverse something intelligible common to them may be abstracted. But this is contrary to the nature of the intellect; for then the intellect would seem not to be distinct from the imagination. It seems, therefore, to follow that there is one intellect in all men.

  Objection 5: Further, when the disciple receives knowledge from the master, it cannot be said that the master's knowledge begets knowledge in the disciple, because then also knowledge would be an active form, such as heat is, which is clearly false. It seems, therefore, that the same individual knowledge which is in the master is communicated to the disciple; which cannot be, unless there is one intellect in both. Seemingly, therefore, the intellect of the disciple and master is but one; and, consequently, the same applies to all men.

  Objection 6: Further, Augustine (De Quant. Animae xxxii) says: "If I were to say that there are many human souls, I should laugh at myself." But the soul seems to be one chiefly on account of the intellect. Therefore there is one intellect of all men.

  On the contrary, The Philosopher says (Phys. ii, 3) that the relation of universal causes to universals is like the relation of particular causes to individuals. But it is impossible that a soul, one in species, should belong to animals of different species. Therefore it is impossible that one individual intellectual soul should belong to several individuals.

  I answer that, It is absolutely impossible for one intellect to belong to all men. This is clear if, as Plato maintained, man is the intellect itself. For it would follow that Socrates and Plato are one man; and that they are not distinct from each other, except by something outside the essence of each. The distinction between Socrates and Plato would be no other than that of one man with a tunic and another with a cloak; which is quite absurd.

   It is likewise clear that this is impossible if, according to the opinion of Aristotle (De Anima ii, 2), it is supposed that the intellect is a part or a power of the soul which is the form of man. For it is impossible for many distinct individuals to have one form, as it is impossible for them to have one existence, for the form is the principle of existence.

   Again, this is clearly impossible, whatever one may hold as to the manner of the union of the intellect to this or that man. For it is manifest that, supposing there is one principal agent, and two instruments, we can say that there is one agent absolutely, but several actions; as when one man touches several things with his two hands, there will be one who touches, but two contacts. If, on the contrary, we suppose one instrument and several principal agents, we might say that there are several agents, but one act; for example, if there be many drawing a ship by means of a rope; there will be many drawing, but one pull. If, however, there is one principal agent, and one instrument, we say that there is one agent and one action, as when the smith strikes with one hammer, there is one striker and one stroke. Now it is clear that no matter how the intellect is united or coupled to this or that man, the intellect has the precedence of all the other things which appertain to man; for the sensitive powers obey the intellect, and are at its service. Therefore, if we suppose two men to have several intellects and one sense---for instance, if two men had one eye---there would be several seers, but one sight. But if there is one intellect, no matter how diverse may be all those things of which the intellect makes use as instruments, in no way is it possible to say that Socrates and Plato are otherwise than one understanding man. And if to this we add that to understand, which is the act of the intellect, is not affected by any organ other than the intellect itself; it will further follow that there is but one agent and one action: that is to say that all men are but one "understander," and have but one act of understanding, in regard, that is, of one intelligible object.

   However, it would be possible to distinguish my intellectual action form yours by the distinction of the phantasms---that is to say, were there one phantasm of a stone in me, and another in you---if the phantasm itself, as it is one thing in me and another in you, were a form of the possible intellect; since the same agent according to divers forms produces divers actions; as, according to divers forms of things with regard to the same eye, there are divers visions. But the phantasm itself is not a form of the possible intellect; it is the intelligible species abstracted from the phantasm that is a form. Now in one intellect, from different phantasms of the same species, only one intelligible species is abstracted; as appears in one man, in whom there may be different phantasms of a stone; yet from all of them only one intelligible species of a stone is abstracted; by which the intellect of that one man, by one operation, understands the nature of a stone, notwithstanding the diversity of phantasms. Therefore, if there were one intellect for all men, the diversity of phantasms which are in this one and that one would not cause a diversity of intellectual operation in this man and that man. It follows, therefore, that it is altogether impossible and unreasonable to maintain that there exists one intellect for all men.

  Reply to Objection 1: Although the intellectual soul, like an angel, has no matter from which it is produced, yet it is the form of a certain matter; in which it is unlike an angel. Therefore, according to the division of matter, there are many souls of one species; while it is quite impossible for many angels to be of one species.

  Reply to Objection 2: Everything has unity in the same way that it has being; consequently we must judge of the multiplicity of a thing as we judge of its being. Now it is clear that the intellectual soul, by virtue of its very being, is united to the body as its form; yet, after the dissolution of the body, the intellectual soul retains its own being. In like manner the multiplicity of souls is in proportion to the multiplicity of the bodies; yet, after the dissolution of the bodies, the souls retain their multiplied being.

  Reply to Objection 3: Individuality of the intelligent being, or of the species whereby it understands, does not exclude the understanding of universals; otherwise, since separate intellects are subsistent substances, and consequently individual, they could not understand universals. But the materiality of the knower, and of the species whereby it knows, impedes the knowledge of the universal. For as every action is according to the mode of the form by which the agent acts, as heating is according to the mode of the heat; so knowledge is according to the mode of the species by which the knower knows. Now it is clear that common nature becomes distinct and multiplied by reason of the individuating principles which come from the matter. Therefore if the form, which is the means of knowledge, is material---that is, not abstracted from material conditions---its likeness to the nature of a species or genus will be according to the distinction and multiplication of that nature by means of individuating principles; so that knowledge of the nature of a thing in general will be impossible. But if the species be abstracted from the conditions of individual matter, there will be a likeness of the nature without those things which make it distinct and multiplied; thus there will be knowledge of the universal. Nor does it matter, as to this particular point, whether there be one intellect or many; because, even if there were but one, it would necessarily be an individual intellect, and the species whereby it understands, an individual species.

  Reply to Objection 4: Whether the intellect be one or many, what is understood is one; for what is understood is in the intellect, not according to its own nature, but according to its likeness; for "the stone is not in the soul, but its likeness is," as is said, De Anima iii, 8. Yet it is the stone which is understood, not the likeness of the stone; except by a reflection of the intellect on itself: otherwise, the objects of sciences would not be things, but only intelligible species. Now it happens that different things, according to different forms, are likened to the same thing. And since knowledge is begotten according to the assimilation of the knower to the thing known, it follows that the same thing may happen to be known by several knowers; as is apparent in regard to the senses; for several see the same color, according to different likenesses. In the same way several intellects understand one object understood. But there is this difference, according to the opinion of Aristotle, between the sense and the intelligence---that a thing is perceived by the sense according to the disposition which it has outside the soul ---that is, in its individuality; whereas the nature of the thing understood is indeed outside the soul, but the mode according to which it exists outside the soul is not the mode according to which it is understood. For the common nature is understood as apart from the individuating principles; whereas such is not its mode of existence outside the soul. But, according to the opinion of Plato, the thing understood exists outside the soul in the same condition as those under which it is understood; for he supposed that the natures of things exist separate from matter.

  Reply to Objection 5: One knowledge exists in the disciple and another in the master. How it is caused will be shown later on (Question [117], Article [1]).

  Reply to Objection 6: Augustine denies a plurality of souls, that would involve a plurality of species.
 
Article: 3

Whether besides the intellectual soul there are in man other souls essentially different from one another?

  Objection 1: It would seem that besides the intellectual soul there are in man other souls essentially different from one another, such as the sensitive soul and the nutritive soul. For corruptible and incorruptible are not of the same substance. But the intellectual soul is incorruptible; whereas the other souls, as the sensitive and the nutritive, are corruptible, as was shown above (Question [75], Article [6]). Therefore in man the essence of the intellectual soul, the sensitive soul, and the nutritive soul, cannot be the same.

  Objection 2: Further, if it be said that the sensitive soul in man is incorruptible; on the contrary, "corruptible and incorruptible differ generically," says the Philosopher, Metaph. x (Did. ix, 10). But the sensitive soul in the horse, the lion, and other brute animals, is corruptible. If, therefore, in man it be incorruptible, the sensitive soul in man and brute animals will not be of the same "genus." Now an animal is so called from its having a sensitive soul; and, therefore, "animal" will not be one genus common to man and other animals, which is absurd.

  Objection 3: Further, the Philosopher says, Metaph. viii (Did. vii, 2), that the genus is taken from the matter, and difference from the form. But "rational," which is the difference constituting man, is taken from the intellectual soul; while he is called "animal" by reason of his having a body animated by a sensitive soul. Therefore the intellectual soul may be compared to the body animated by a sensitive soul, as form to matter. Therefore in man the intellectual soul is not essentially the same as the sensitive soul, but presupposes it as a material subject.

  On the contrary, It is said in the book De Ecclesiasticis Dogmatibus xv: "Nor do we say that there are two souls in one man, as James and other Syrians write; one, animal, by which the body is animated, and which is mingled with the blood; the other, spiritual, which obeys the reason; but we say that it is one and the same soul in man, that both gives life to the body by being united to it, and orders itself by its own reasoning."

  I answer that, Plato held that there were several souls in one body, distinct even as to organs, to which souls he referred the different vital actions, saying that the nutritive power is in the liver, the concupiscible in the heart, and the power of knowledge in the brain. Which opinion is rejected by Aristotle (De Anima ii, 2), with regard to those parts of the soul which use corporeal organs; for this reason, that in those animals which continue to live when they have been divided in each part are observed the operations of the soul, as sense and appetite. Now this would not be the case if the various principles of the soul's operations were essentially different, and distributed in the various parts of the body. But with regard to the intellectual part, he seems to leave it in doubt whether it be "only logically" distinct from the other parts of the soul, "or also locally."

   The opinion of Plato might be maintained if, as he held, the soul was supposed to be united to the body, not as its form, but as its motor. For it involves nothing unreasonable that the same movable thing be moved by several motors; and still less if it be moved according to its various parts. If we suppose, however, that the soul is united to the body as its form, it is quite impossible for several essentially different souls to be in one body. This can be made clear by three different reasons.

   In the first place, an animal would not be absolutely one, in which there were several souls. For nothing is absolutely one except by one form, by which a thing has existence: because a thing has from the same source both existence and unity; and therefore things which are denominated by various forms are not absolutely one; as, for instance, "a white man." If, therefore, man were 'living' by one form, the vegetative soul, and 'animal' by another form, the sensitive soul, and "man" by another form, the intellectual soul, it would follow that man is not absolutely one. Thus Aristotle argues, Metaph. viii (Did. vii, 6), against Plato, that if the idea of an animal is distinct from the idea of a biped, then a biped animal is not absolutely one. For this reason, against those who hold that there are several souls in the body, he asks (De Anima i, 5), "what contains them?"---that is, what makes them one? It cannot be said that they are united by the one body; because rather does the soul contain the body and make it one, than the reverse.

   Secondly, this is proved to be impossible by the manner in which one thing is predicated of another. Those things which are derived from various forms are predicated of one another, either accidentally, (if the forms are not ordered to one another, as when we say that something white is sweet), or essentially, in the second manner of essential predication, (if the forms are ordered one to another, the subject belonging to the definition of the predicate; as a surface is presupposed to color; so that if we say that a body with a surface is colored, we have the second manner of essential predication.) Therefore, if we have one form by which a thing is an animal, and another form by which it is a man, it follows either that one of these two things could not be predicated of the other, except accidentally, supposing these two forms not to be ordered to one another---or that one would be predicated of the other according to the second manner of essential predication, if one soul be presupposed to the other. But both of these consequences are clearly false: because "animal" is predicated of man essentially and not accidentally; and man is not part of the definition of an animal, but the other way about. Therefore of necessity by the same form a thing is animal and man; otherwise man would not really be the thing which is an animal, so that animal can be essentially predicated of man.

   Thirdly, this is shown to be impossible by the fact that when one operation of the soul is intense it impedes another, which could never be the case unless the principle of action were essentially one.

   We must therefore conclude that in man the sensitive soul, the intellectual soul, and the nutritive soul are numerically one soul. This can easily be explained, if we consider the differences of species and forms. For we observe that the species and forms of things differ from one another, as the perfect and imperfect; as in the order of things, the animate are more perfect than the inanimate, and animals more perfect than plants, and man than brute animals; and in each of these genera there are various degrees. For this reason Aristotle, Metaph. viii (Did. vii, 3), compares the species of things to numbers, which differ in species by the addition or subtraction of unity. And (De Anima ii, 3) he compares the various souls to the species of figures, one of which contains another; as a pentagon contains and exceeds a tetragon. Thus the intellectual soul contains virtually whatever belongs to the sensitive soul of brute animals, and to the nutritive souls of plants. Therefore, as a surface which is of a pentagonal shape, is not tetragonal by one shape, and pentagonal by another---since a tetragonal shape would be superfluous as contained in the pentagonal---so neither is Socrates a man by one soul, and animal by another; but by one and the same soul he is both animal and man.

  Reply to Objection 1: The sensitive soul is incorruptible, not by reason of its being sensitive, but by reason of its being intellectual. When, therefore, a soul is sensitive only, it is corruptible; but when with sensibility it has also intellectuality, it is incorruptible. For although sensibility does not give incorruptibility, yet it cannot deprive intellectuality of its incorruptibility.

  Reply to Objection 2: Not forms, but composites, are classified either generically or specifically. Now man is corruptible like other animals. And so the difference of corruptible and incorruptible which is on the part of the forms does not involve a generic difference between man and the other animals.

  Reply to Objection 3: The embryo has first of all a soul which is merely sensitive, and when this is removed, it is supplanted by a more perfect soul, which is both sensitive and intellectual: as will be shown further on (Question [118], Article [2], ad 2).

  Reply to Objection 4: We must not consider the diversity of natural things as proceeding from the various logical notions or intentions, which flow from our manner of understanding, because reason can apprehend one and the same thing in various ways. Therefore since, as we have said, the intellectual soul contains virtually what belongs to the sensitive soul, and something more, reason can consider separately what belongs to the power of the sensitive soul, as something imperfect and material. And because it observes that this is something common to man and to other animals, it forms thence the notion of the "genus"; while that wherein the intellectual soul exceeds the sensitive soul, it takes as formal and perfecting; thence it gathers the "difference" of man.
 
Article: 4

Whether in man there is another form besides the intellectual soul?

  Objection 1: It would seem that in man there is another form besides the intellectual soul. For the Philosopher says (De Anima ii, 1), that "the soul is the act of a physical body which has life potentially." Therefore the soul is to the body as a form of matter. But the body has a substantial form by which it is a body. Therefore some other substantial form in the body precedes the soul.

  Objection 2: Further, man moves himself as every animal does. Now everything that moves itself is divided into two parts, of which one moves, and the other is moved, as the Philosopher proves (Phys. viii, 5). But the part which moves is the soul. Therefore the other part must be such that it can be moved. But primary matter cannot be moved (Phys. v, 1), since it is a being only potentially; indeed everything that is moved is a body. Therefore in man and in every animal there must be another substantial form, by which the body is constituted.

  Objection 3: Further, the order of forms depends on their relation to primary matter; for "before" and "after" apply by comparison to some beginning. Therefore if there were not in man some other substantial form besides the rational soul, and if this were to inhere immediately to primary matter; it would follow that it ranks among the most imperfect forms which inhere to matter immediately.

  Objection 4: Further, the human body is a mixed body. Now mingling does not result from matter alone; for then we should have mere corruption. Therefore the forms of the elements must remain in a mixed body; and these are substantial forms. Therefore in the human body there are other substantial forms besides the intellectual soul.

  On the contrary, Of one thing there is but one substantial being. But the substantial form gives substantial being. Therefore of one thing there is but one substantial form. But the soul is the substantial form of man. Therefore it is impossible for there to be in man another substantial form besides the intellectual soul.

  I answer that, If we suppose that the intellectual soul is not united to the body as its form, but only as its motor, as the Platonists maintain, it would necessarily follow that in man there is another substantial form, by which the body is established in its being as movable by the soul. If, however, the intellectual soul be united to the body as its substantial form, as we have said above (Article [1]), it is impossible for another substantial form besides the intellectual soul to be found in man.

   In order to make this evident, we must consider that the substantial form differs from the accidental form in this, that the accidental form does not make a thing to be "simply," but to be "such," as heat does not make a thing to be simply, but only to be hot. Therefore by the coming of the accidental form a thing is not said to be made or generated simply, but to be made such, or to be in some particular condition; and in like manner, when an accidental form is removed, a thing is said to be corrupted, not simply, but relatively. Now the substantial form gives being simply; therefore by its coming a thing is said to be generated simply; and by its removal to be corrupted simply. For this reason, the old natural philosophers, who held that primary matter was some actual being---for instance, fire or air, or something of that sort---maintained that nothing is generated simply, or corrupted simply; and stated that "every becoming is nothing but an alteration," as we read, Phys. i, 4. Therefore, if besides the intellectual soul there pre-existed in matter another substantial form by which the subject of the soul were made an actual being, it would follow that the soul does not give being simply; and consequently that it is not the substantial form: and so at the advent of the soul there would not be simple generation; nor at its removal simple corruption, all of which is clearly false.

   Whence we must conclude, that there is no other substantial form in man besides the intellectual soul; and that the soul, as it virtually contains the sensitive and nutritive souls, so does it virtually contain all inferior forms, and itself alone does whatever the imperfect forms do in other things. The same is to be said of the sensitive soul in brute animals, and of the nutritive soul in plants, and universally of all more perfect forms with regard to the imperfect.

  Reply to Objection 1: Aristotle does not say that the soul is the act of a body only, but "the act of a physical organic body which has life potentially"; and that this potentiality "does not reject the soul." Whence it is clear that when the soul is called the act, the soul itself is included; as when we say that heat is the act of what is hot, and light of what is lucid; not as though lucid and light were two separate things, but because a thing is made lucid by the light. In like manner, the soul is said to be the "act of a body," etc., because by the soul it is a body, and is organic, and has life potentially. Yet the first act is said to be in potentiality to the second act, which is operation; for such a potentiality "does not reject"---that is, does not exclude---the soul.

  Reply to Objection 2: The soul does not move the body by its essence, as the form of the body, but by the motive power, the act of which presupposes the body to be already actualized by the soul: so that the soul by its motive power is the part which moves; and the animate body is the part moved.

  Reply to Objection 3: We observe in matter various degrees of perfection, as existence, living, sensing, and understanding. Now what is added is always more perfect. Therefore that form which gives matter only the first degree of perfection is the most imperfect; while that form which gives the first, second, and third degree, and so on, is the most perfect: and yet it inheres to matter immediately.

  Reply to Objection 4: Avicenna held that the substantial forms of the elements remain entire in the mixed body; and that the mixture is made by the contrary qualities of the elements being reduced to an average. But this is impossible, because the various forms of the elements must necessarily be in various parts of matter; for the distinction of which we must suppose dimensions, without which matter cannot be divisible. Now matter subject to dimension is not to be found except in a body. But various bodies cannot be in the same place. Whence it follows that elements in the mixed body would be distinct as to situation. And then there would not be a real mixture which is in respect of the whole; but only a mixture apparent to sense, by the juxtaposition of particles.

   Averroes maintained that the forms of elements, by reason of their imperfection, are a medium between accidental and substantial forms, and so can be "more" or "less"; and therefore in the mixture they are modified and reduced to an average, so that one form emerges from them. But this is even still more impossible. For the substantial being of each thing consists in something indivisible, and every addition and subtraction varies the species, as in numbers, as stated in Metaph. viii (Did. vii, 3); and consequently it is impossible for any substantial form to receive "more" or "less." Nor is it less impossible for anything to be a medium between substance and accident.

   Therefore we must say, in accordance with the Philosopher (De Gener. i, 10), that the forms of the elements remain in the mixed body, not actually but virtually. For the proper qualities of the elements remain, though modified; and in them is the power of the elementary forms. This quality of the mixture is the proper disposition for the substantial form of the mixed body; for instance, the form of a stone, or of any sort of soul.
 
Article: 5 

Whether the intellectual soul is properly united to such a body?

  Objection 1: It would seem that the intellectual soul is improperly united to such a body. For matter must be proportionate to the form. But the intellectual soul is incorruptible. Therefore it is not properly united to a corruptible body.

  Objection 2: Further, the intellectual soul is a perfectly immaterial form; a proof whereof is its operation in which corporeal matter does not share. But the more subtle is the body, the less has it of matter. Therefore the soul should be united to a most subtle body, to fire, for instance, and not to a mixed body, still less to a terrestrial body.

  Objection 3: Further, since the form is the principle of the species, one form cannot produce a variety of species. But the intellectual soul is one form. Therefore, it should not be united to a body which is composed of parts belonging to various species.

  Objection 4: Further, what is susceptible of a more perfect form should itself be more perfect. But the intellectual soul is the most perfect of souls. Therefore since the bodies of other animals are naturally provided with a covering, for instance, with hair instead of clothes, and hoofs instead of shoes; and are, moreover, naturally provided with arms, as claws, teeth, and horns; it seems that the intellectual soul should not have been united to a body which is imperfect as being deprived of the above means of protection.

  On the contrary, The Philosopher says (De Anima ii, 1), that "the soul is the act of a physical organic body having life potentially."

  I answer that, Since the form is not for the matter, but rather the matter for the form, we must gather from the form the reason why the matter is such as it is; and not conversely. Now the intellectual soul, as we have seen above (Question [55], Article [2]) in the order of nature, holds the lowest place among intellectual substances; inasmuch as it is not naturally gifted with the knowledge of truth, as the angels are; but has to gather knowledge from individual things by way of the senses, as Dionysius says (Div. Nom. vii). But nature never fails in necessary things: therefore the intellectual soul had to be endowed not only with the power of understanding, but also with the power of feeling. Now the action of the senses is not performed without a corporeal instrument. Therefore it behooved the intellectual soul to be united to a body fitted to be a convenient organ of sense.

   Now all the other senses are based on the sense of touch. But the organ of touch requires to be a medium between contraries, such as hot and cold, wet and dry, and the like, of which the sense of touch has the perception; thus it is in potentiality with regard to contraries, and is able to perceive them. Therefore the more the organ of touch is reduced to an equable complexion, the more sensitive will be the touch. But the intellectual soul has the power of sense in all its completeness; because what belongs to the inferior nature pre-exists more perfectly in the superior, as Dionysius says (Div. Nom. v). Therefore the body to which the intellectual soul is united should be a mixed body, above others reduced to the most equable complexion. For this reason among animals, man has the best sense of touch. And among men, those who have the best sense of touch have the best intelligence. A sign of which is that we observe "those who are refined in body are well endowed in mind," as stated in De Anima ii, 9.

  Reply to Objection 1: Perhaps someone might attempt to answer this by saying that before sin the human body was incorruptible. This answer does not seem sufficient; because before sin the human body was immortal not by nature, but by a gift of Divine grace; otherwise its immortality would not be forfeited through sin, as neither was the immortality of the devil.

   Therefore we answer otherwise by observing that in matter two conditions are to be found; one which is chosen in order that the matter be suitable to the form; the other which follows by force of the first disposition. The artisan, for instance, for the form of the saw chooses iron adapted for cutting through hard material; but that the teeth of the saw may become blunt and rusted, follows by force of the matter itself. So the intellectual soul requires a body of equable complexion, which, however, is corruptible by force of its matter. If, however, it be said that God could avoid this, we answer that in the formation of natural things we do not consider what God might do; but what is suitable to the nature of things, as Augustine says (Gen. ad lit. ii, 1). God, however, provided in this case by applying a remedy against death in the gift of grace.

  Reply to Objection 2: A body is not necessary to the intellectual soul by reason of its intellectual operation considered as such; but on account of the sensitive power, which requires an organ of equable temperament. Therefore the intellectual soul had to be united to such a body, and not to a simple element, or to a mixed body, in which fire was in excess; because otherwise there could not be an equability of temperament. And this body of an equable temperament has a dignity of its own by reason of its being remote from contraries, thereby resembling in a way a heavenly body.

  Reply to Objection 3: The parts of an animal, for instance, the eye, hand, flesh, and bones, and so forth, do not make the species; but the whole does, and therefore, properly speaking, we cannot say that these are of different species, but that they are of various dispositions. This is suitable to the intellectual soul, which, although it be one in its essence, yet on account of its perfection, is manifold in power: and therefore, for its various operations it requires various dispositions in the parts of the body to which it is united. For this reason we observe that there is a greater variety of parts in perfect than in imperfect animals; and in these a greater variety than in plants.

  Reply to Objection 4: The intellectual soul as comprehending universals, has a power extending to the infinite; therefore it cannot be limited by nature to certain fixed natural notions, or even to certain fixed means whether of defence or of clothing, as is the case with other animals, the souls of which are endowed with knowledge and power in regard to fixed particular things. Instead of all these, man has by nature his reason and his hands, which are "the organs of organs" (De Anima iii), since by their means man can make for himself instruments of an infinite variety, and for any number of purposes.


Article: 6 

Whether the intellectual soul is united to the body through the medium of accidental dispositions?

  Objection 1: It would seem that the intellectual soul is united to the body through the medium of accidental dispositions. For every form exists in its proper disposed matter. But dispositions to a form are accidents. Therefore we must presuppose accidents to be in matter before the substantial form; and therefore before the soul, since the soul is a substantial form.

  Objection 2: Further, various forms of one species require various parts of matter. But various parts of matter are unintelligible without division in measurable quantities. Therefore we must suppose dimensions in matter before the substantial forms, which are many belonging to one species.

  Objection 3: Further, what is spiritual is connected with what is corporeal by virtual contact. But the virtue of the soul is its power. Therefore it seems that the soul is united to the body by means of a power, which is an accident.

  On the contrary, Accident is posterior to substance, both in the order of time and in the order of reason, as the Philosopher says, Metaph. vii (Did. vi, 1). Therefore it is unintelligible that any accidental form exist in matter before the soul, which is the substantial form.

  I answer that, If the soul were united to the body, merely as a motor, there would be nothing to prevent the existence of certain dispositions mediating between the soul and the body; on the contrary, they would be necessary, for on the part of the soul would be required the power to move the body; and on the part of the body, a certain aptitude to be moved by the soul.

   If, however, the intellectual soul is united to the body as the substantial form, as we have already said above (Article [1]), it is impossible for any accidental disposition to come between the body and the soul, or between any substantial form whatever and its matter. The reason is because since matter is in potentiality to all manner of acts in a certain order, what is absolutely first among the acts must be understood as being first in matter. Now the first among all acts is existence. Therefore, it is impossible for matter to be apprehended as hot, or as having quantity, before it is actual. But matter has actual existence by the substantial form, which makes it to exist absolutely, as we have said above (Article [4]). Wherefore it is impossible for any accidental dispositions to pre-exist in matter before the substantial form, and consequently before the soul.

  Reply to Objection 1: As appears from what has been already said (Article [4]), the more perfect form virtually contains whatever belongs to the inferior forms; therefore while remaining one and the same, it perfects matter according to the various degrees of perfection. For the same essential form makes man an actual being, a body, a living being, an animal, and a man. Now it is clear that to every "genus" follow its own proper accidents. Therefore as matter is apprehended as perfected in its existence, before it is understood as corporeal, and so on; so those accidents which belong to existence are understood to exist before corporeity; and thus dispositions are understood in matter before the form, not as regards all its effects, but as regards the subsequent effect.

  Reply to Objection 2: Dimensions of quantity are accidents consequent to the corporeity which belongs to the whole matter. Wherefore matter, once understood as corporeal and measurable, can be understood as distinct in its various parts, and as receptive of different forms according to the further degrees of perfection. For although it is essentially the same form which gives matter the various degrees of perfection, as we have said (ad 1), yet it is considered as different when brought under the observation of reason.

  Reply to Objection 3: A spiritual substance which is united to a body as its motor only, is united thereto by power or virtue. But the intellectual soul is united by its very being to the body as a form; and yet it guides and moves the body by its power and virtue.

Article: 7 

Whether the soul is united to the animal body by means of a body?

  Objection 1: It seems that the soul is united to the animal body by means of a body. For Augustine says (Gen. ad lit. vii, 19), that "the soul administers the body by light," that is, by fire, "and by air, which is most akin to a spirit." But fire and air are bodies. Therefore the soul is united to the human body by means of a body.

  Objection 2: Further, a link between two things seems to be that thing the removal of which involves the cessation of their union. But when breathing ceases, the soul is separated from the body. Therefore the breath, which is a subtle body, is the means of union between soul and body.

  Objection 3: Further, things which are very distant from one another, are not united except by something between them. But the intellectual soul is very distant from the body, both because it is incorporeal, and because it is incorruptible. Therefore it seems to be united to the body by means of an incorruptible body, and such would be some heavenly light, which would harmonize the elements, and unite them together.

  On the contrary, The Philosopher says (De Anima ii, 1): "We need not ask if the soul and body are one, as neither do we ask if wax and its shape are one." But the shape is united to the wax without a body intervening. Therefore also the soul is thus united to the body.

  I answer that, If the soul, according to the Platonists, were united to the body merely as a motor, it would be right to say that some other bodies must intervene between the soul and body of man, or any animal whatever; for a motor naturally moves what is distant from it by means of something nearer.

   If, however, the soul is united to the body as its form, as we have said (Article [1]), it is impossible for it to be united by means of another body. The reason of this is that a thing is one, according as it is a being. Now the form, through itself, makes a thing to be actual since it is itself essentially an act; nor does it give existence by means of something else. Wherefore the unity of a thing composed of matter and form, is by virtue of the form itself, which by reason of its very nature is united to matter as its act. Nor is there any other cause of union except the agent, which causes matter to be in act, as the Philosopher says, Metaph. viii (Did. vii, 6).

   From this it is clear how false are the opinions of those who maintained the existence of some mediate bodies between the soul and body of man. Of these certain Platonists said that the intellectual soul has an incorruptible body naturally united to it, from which it is never separated, and by means of which it is united to the corruptible body of man. Others said that the soul is united to the body by means of a corporeal spirit. Others said it is united to the body by means of light, which, they say, is a body and of the nature of the fifth essence; so that the vegetative soul would be united to the body by means of the light of the sidereal heaven; the sensible soul, by means of the light of the crystal heaven; and the intellectual soul by means of the light of the empyrean heaven. Now all this is fictious and ridiculous: for light is not a body; and the fifth essence does not enter materially into the composition of a mixed body (since it is unchangeable), but only virtually: and lastly, because the soul is immediately united to the body as the form to matter.

  Reply to Objection 1: Augustine speaks there of the soul as it moves the body; whence he uses the word "administration." It is true that it moves the grosser parts of the body by the more subtle parts. And the first instrument of the motive power is a kind of spirit, as the Philosopher says in De causa motus animalium (De mot. animal. x).

  Reply to Objection 2: The union of soul and body ceases at the cessation of breath, not because this is the means of union, but because of the removal of that disposition by which the body is disposed for such a union. Nevertheless the breath is a means of moving, as the first instrument of motion.

  Reply to Objection 3: The soul is indeed very distant from the body, if we consider the condition of each separately: so that if each had a separate existence, many means of connection would have to intervene. But inasmuch as the soul is the form of the body, it has not an existence apart from the existence of the body, but by its own existence is united to the body immediately. This is the case with every form which, if considered as an act, is very distant from matter, which is a being only in potentiality.
 
Article: 8 

Whether the soul is in each part of the body?

  Objection 1: It would seem that the whole soul is not in each part of the body; for the Philosopher says in De causa motus animalium (De mot. animal. x): "It is not necessary for the soul to be in each part of the body; it suffices that it be in some principle of the body causing the other parts to live, for each part has a natural movement of its own."

  Objection 2: Further, the soul is in the body of which it is the act. But it is the act of an organic body. Therefore it exists only in an organic body. But each part of the human body is not an organic body. Therefore the whole soul is not in each part.

  Objection 3: Further, the Philosopher says (De Anima. ii, 1) that the relation of a part of the soul to a part of the body, such as the sight to the pupil of the eye, is the same as the relation of the soul to the whole body of an animal. If, therefore, the whole soul is in each part of the body, it follows that each part of the body is an animal.

  Objection 4: Further, all the powers of the soul are rooted in the essence of the soul. If, therefore, the whole soul be in each part of the body, it follows that all the powers of the soul are in each part of the body; thus the sight will be in the ear, and hearing in the eye, and this is absurd.

  Objection 5: Further, if the whole soul is in each part of the body, each part of the body is immediately dependent on the soul. Thus one part would not depend on another; nor would one part be nobler than another; which is clearly untrue. Therefore the soul is not in each part of the body.

  On the contrary, Augustine says (De Trin. vi, 6), that "in each body the whole soul is in the whole body, and in each part is entire."

  I answer that, As we have said, if the soul were united to the body merely as its motor, we might say that it is not in each part of the body, but only in one part through which it would move the others. But since the soul is united to the body as its form, it must necessarily be in the whole body, and in each part thereof. For it is not an accidental form, but the substantial form of the body. Now the substantial form perfects not only the whole, but each part of the whole. For since a whole consists of parts, a form of the whole which does not give existence to each of the parts of the body, is a form consisting in composition and order, such as the form of a house; and such a form is accidental. But the soul is a substantial form; and therefore it must be the form and the act, not only of the whole, but also of each part. Therefore, on the withdrawal of the soul, as we do not speak of an animal or a man unless equivocally, as we speak of a painted animal or a stone animal; so is it with the hand, the eye, the flesh and bones, as the Philosopher says (De Anima ii, 1). A proof of which is, that on the withdrawal of the soul, no part of the body retains its proper action; although that which retains its species, retains the action of the species. But act is in that which it actuates: wherefore the soul must be in the whole body, and in each part thereof.

   That it is entire in each part thereof, may be concluded from this, that since a whole is that which is divided into parts, there are three kinds of totality, corresponding to three kinds of division. There is a whole which is divided into parts of quantity, as a whole line, or a whole body. There is also a whole which is divided into logical and essential parts: as a thing defined is divided into the parts of a definition, and a composite into matter and form. There is, further, a third kind of whole which is potential, divided into virtual parts. The first kind of totality does not apply to forms, except perhaps accidentally; and then only to those forms, which have an indifferent relationship to a quantitative whole and its parts; as whiteness, as far as its essence is concerned, is equally disposed to be in the whole surface and in each part of the surface; and, therefore, the surface being divided, the whiteness is accidentally divided. But a form which requires variety in the parts, such as a soul, and specially the soul of perfect animals, is not equally related to the whole and the parts: hence it is not divided accidentally when the whole is divided. So therefore quantitative totality cannot be attributed to the soul, either essentially or accidentally. But the second kind of totality, which depends on logical and essential perfection, properly and essentially belongs to forms: and likewise the virtual totality, because a form is the principle of operation.

   Therefore if it be asked whether the whole whiteness is in the whole surface and in each part thereof, it is necessary to distinguish. If we mean quantitative totality which whiteness has accidentally, then the whole whiteness is not in each part of the surface. The same is to be said of totality of power: since the whiteness which is in the whole surface moves the sight more than the whiteness which is in a small part thereof. But if we mean totality of species and essence, then the whole whiteness is in each part of a surface.

   Since, however, the soul has not quantitative totality, neither essentially, nor accidentally, as we have seen; it is enough to say that the whole soul is in each part of the body, by totality of perfection and of essence, but not by totality of power. For it is not in each part of the body, with regard to each of its powers; but with regard to sight, it is in the eye; and with regard to hearing, it is in the ear; and so forth. We must observe, however, that since the soul requires variety of parts, its relation to the whole is not the same as its relation to the parts; for to the whole it is compared primarily and essentially, as to its proper and proportionate perfectible; but to the parts, secondarily, inasmuch as they are ordained to the whole.

  Reply to Objection 1: The Philosopher is speaking there of the motive power of the soul.

  Reply to Objection 2: The soul is the act of an organic body, as of its primary and proportionate perfectible.

  Reply to Objection 3: An animal is that which is composed of a soul and a whole body, which is the soul's primary and proportionate perfectible. Thus the soul is not in a part. Whence it does not follow that a part of an animal is an animal.

  Reply to Objection 4: Some of the powers of the soul are in it according as it exceeds the entire capacity of the body, namely the intellect and the will; whence these powers are not said to be in any part of the body. Other powers are common to the soul and body; wherefore each of these powers need not be wherever the soul is, but only in that part of the body, which is adapted to the operation of such a power.

  Reply to Objection 5: One part of the body is said to be nobler than another, on account of the various powers, of which the parts of the body are the organs. For that part which is the organ of a nobler power, is a nobler part of the body: as also is that part which serves the same power in a nobler manner.

Question: 77 OF THOSE THINGS WHICH BELONG TO THE POWERS OF THE SOUL IN GENERAL (EIGHT ARTICLES)

   We proceed to consider those things which belong to the powers of the soul; first, in general, secondly, in particular. Under the first head there are eight points of inquiry:

    (1) Whether the essence of the soul is its power?

    (2) Whether there is one power of the soul, or several?

    (3) How the powers of the soul are distinguished from one another?

    (4) Of the orders of the powers, one to another;

    (5) Whether the powers of the soul are in it as in their subject?

    (6) Whether the powers flow from the essence of the soul?

    (7) Whether one power rises from another?

    (8) Whether all the powers of the soul remain in the soul after death?
 
Article: 1

Whether the essence of the soul is its power?

  Objection 1: It would seem that the essence of the soul is its power. For Augustine says (De Trin. ix, 4), that "mind, knowledge, and love are in the soul substantially, or, which is the same thing, essentially": and (De Trin. x, 11), that "memory, understanding, and will are one life, one mind, one essence."

  Objection 2: Further, the soul is nobler than primary matter. But primary matter is its own potentiality. Much more therefore is the soul its own power.

  Objection 3: Further, the substantial form is simpler than the accidental form; a sign of which is that the substantial form is not intensified or relaxed, but is indivisible. But the accidental form is its own power. Much more therefore is that substantial form which is the soul.

  Objection 4: Further, we sense by the sensitive power and we understand by the intellectual power. But "that by which we first sense and understand" is the soul, according to the Philosopher (De Anima ii, 2). Therefore the soul is its own power.

  Objection 5: Further, whatever does not belong to the essence is an accident. Therefore if the power of the soul is something else besides the essence thereof, it is an accident, which is contrary to Augustine, who says that the foregoing (see OBJ 1) "are not in the soul as in a subject as color or shape, or any other quality, or quantity, are in a body; for whatever is so, does not exceed the subject in which it is: Whereas the mind can love and know other things" (De Trin. ix, 4).

  Objection 6: Further, " a simple form cannot be a subject." But the soul is a simple form; since it is not composed of matter and form, as we have said above (Question [75], Article [5]). Therefore the power of the soul cannot be in it as in a subject.

  Objection 7: Further, an accident is not the principle of a substantial difference. But sensitive and rational are substantial differences; and they are taken from sense and reason, which are powers of the soul. Therefore the powers of the soul are not accidents; and so it would seem that the power of the soul is its own essence.

  On the contrary, Dionysius (Coel. Hier. xi) says that "heavenly spirits are divided into essence, power, and operation." Much more, then, in the soul is the essence distinct from the virtue or power.

  I answer that, It is impossible to admit that the power of the soul is its essence, although some have maintained it. For the present purpose this may be proved in two ways. First, because, since power and act divide being and every kind of being, we must refer a power and its act to the same genus. Therefore, if the act be not in the genus of substance, the power directed to that act cannot be in the genus of substance. Now the operation of the soul is not in the genus of substance; for this belongs to God alone, whose operation is His own substance. Wherefore the Divine power which is the principle of His operation is the Divine Essence itself. This cannot be true either of the soul, or of any creature; as we have said above when speaking of the angels (Question [54], Article [3]). Secondly, this may be also shown to be impossible in the soul. For the soul by its very essence is an act. Therefore if the very essence of the soul were the immediate principle of operation, whatever has a soul would always have actual vital actions, as that which has a soul is always an actually living thing. For as a form the soul is not an act ordained to a further act, but the ultimate term of generation. Wherefore, for it to be in potentiality to another act, does not belong to it according to its essence, as a form, but according to its power. So the soul itself, as the subject of its power, is called the first act, with a further relation to the second act. Now we observe that what has a soul is not always actual with respect to its vital operations; whence also it is said in the definition of the soul, that it is "the act of a body having life potentially"; which potentiality, however, "does not exclude the soul." Therefore it follows that the essence of the soul is not its power. For nothing is in potentiality by reason of an act, as act.

  Reply to Objection 1: Augustine is speaking of the mind as it knows and loves itself. Thus knowledge and love as referred to the soul as known and loved, are substantially or essentially in the soul, for the very substance or essence of the soul is known and loved. In the same way are we to understand what he says in the other passage, that those things are "one life, one mind, one essence." Or, as some say, this passage is true in the sense in which the potential whole is predicated of its parts, being midway between the universal whole, and the integral whole. For the universal whole is in each part according to its entire essence and power; as animal in a man and in a horse; and therefore it is properly predicated of each part. But the integral whole is not in each part, neither according to its whole essence, nor according to its whole power. Therefore in no way can it be predicated of each part; yet in a way it is predicated, though improperly, of all the parts together; as if we were to say that the wall, roof, and foundations are a house. But the potential whole is in each part according to its whole essence, not, however, according to its whole power. Therefore in a way it can be predicated of each part, but not so properly as the universal whole. In this sense, Augustine says that the memory, understanding, and the will are the one essence of the soul.

  Reply to Objection 2: The act to which primary matter is in potentiality is the substantial form. Therefore the potentiality of matter is nothing else but its essence.

  Reply to Objection 3: Action belongs to the composite, as does existence; for to act belongs to what exists. Now the composite has substantial existence through the substantial form; and it operates by the power which results from the substantial form. Hence an active accidental form is to the substantial form of the agent (for instance, heat compared to the form of fire) as the power of the soul is to the soul.

  Reply to Objection 4: That the accidental form is a principle of action is due to the substantial form. Therefore the substantial form is the first principle of action; but not the proximate principle. In this sense the Philosopher says that "the soul is that whereby we understand and sense."

  Reply to Objection 5: If we take accident as meaning what is divided against substance, then there can be no medium between substance and accident; because they are divided by affirmation and negation, that is, according to existence in a subject, and non-existence in a subject. In this sense, as the power of the soul is not its essence, it must be an accident; and it belongs to the second species of accident, that of quality. But if we take accident as one of the five universals, in this sense there is a medium between substance and accident. For the substance is all that belongs to the essence of a thing; whereas whatever is beyond the essence of a thing cannot be called accident in this sense; but only what is not caused by the essential principle of the species. For the 'proper' does not belong to the essence of a thing, but is caused by the essential principles of the species; wherefore it is a medium between the essence and accident thus understood. In this sense the powers of the soul may be said to be a medium between substance and accident, as being natural properties of the soul. When Augustine says that knowledge and love are not in the soul as accidents in a subject, this must be understood in the sense given above, inasmuch as they are compared to the soul, not as loving and knowing, but as loved and known. His argument proceeds in this sense; for if love were in the soul loved as in a subject, it would follow that an accident transcends its subject, since even other things are loved through the soul.

  Reply to Objection 6: Although the soul is not composed of matter and form, yet it has an admixture of potentiality, as we have said above (Question [75], Article [5], ad 4); and for this reason it can be the subject of an accident. The statement quoted is verified in God, Who is the Pure Act; in treating of which subject Boethius employs that phrase (De Trin. i).

  Reply to Objection 7: Rational and sensitive, as differences, are not taken from the powers of sense and reason, but from the sensitive and rational soul itself. But because substantial forms, which in themselves are unknown to us, are known by their accidents; nothing prevents us from sometimes substituting accidents for substantial differences.
 
Article: 2 

Whether there are several powers of the soul?

  Objection 1: It would seem that there are not several powers of the soul. For the intellectual soul approaches nearest to the likeness of God. But in God there is one simple power: and therefore also in the intellectual soul.

  Objection 2: Further, the higher a power is, the more unified it is. But the intellectual soul excels all other forms in power. Therefore above all others it has one virtue or power.

  Objection 3: Further, to operate belongs to what is in act. But by the one essence of the soul, man has actual existence in the different degrees of perfection, as we have seen above (Question [76], Articles [3],4). Therefore by the one power of the soul he performs operations of various degrees.

  On the contrary, The Philosopher places several powers in the soul (De Anima ii, 2,3).

  I answer that, Of necessity we must place several powers in the soul. To make this evident, we observe that, as the Philosopher says (De Coelo ii, 12), the lowest order of things cannot acquire perfect goodness, but they acquire a certain imperfect goodness, by few movements; and those which belong to a higher order acquire perfect goodness by many movements; and those yet higher acquire perfect goodness by few movements; and the highest perfection is found in those things which acquire perfect goodness without any movement whatever. Thus he is least of all disposed of health, who can only acquire imperfect health by means of a few remedies; better disposed is he who can acquire perfect health by means of many remedies; and better still, he who can by few remedies; best of all is he who has perfect health without any remedies. We conclude, therefore, that things which are below man acquire a certain limited goodness; and so they have a few determinate operations and powers. But man can acquire universal and perfect goodness, because he can acquire beatitude. Yet he is in the last degree, according to his nature, of those to whom beatitude is possible; therefore the human soul requires many and various operations and powers. But to angels a smaller variety of powers is sufficient. In God there is no power or action beyond His own Essence.

   There is yet another reason why the human soul abounds in a variety of powers---because it is on the confines of spiritual and corporeal creatures; and therefore the powers of both meet together in the soul.

  Reply to Objection 1: The intellectual soul approaches to the Divine likeness, more than inferior creatures, in being able to acquire perfect goodness; although by many and various means; and in this it falls short of more perfect creatures.

  Reply to Objection 2: A unified power is superior if it extends to equal things: but a multiform power is superior to it, if it is over many things.

  Reply to Objection 3: One thing has one substantial existence, but may have several operations. So there is one essence of the soul, with several powers.

Article: 3 

Whether the powers are distinguished by their acts and objects?

  Objection 1: It would seem that the powers of the soul are not distinguished by acts and objects. For nothing is determined to its species by what is subsequent and extrinsic to it. But the act is subsequent to the power; and the object is extrinsic to it. Therefore the soul's powers are not specifically distinct by acts and objects.

  Objection 2: Further, contraries are what differ most from each other. Therefore if the powers are distinguished by their objects, it follows that the same power could not have contrary objects. This is clearly false in almost all the powers; for the power of vision extends to white and black, and the power to taste to sweet and bitter.

  Objection 3: Further, if the cause be removed, the effect is removed. Hence if the difference of powers came from the difference of objects, the same object would not come under different powers. This is clearly false; for the same thing is known by the cognitive power, and desired by the appetitive.

  Objection 4: Further, that which of itself is the cause of anything, is the cause thereof, wherever it is. But various objects which belong to various powers, belong also to some one power; as sound and color belong to sight and hearing, which are different powers, yet they come under the one power of common sense. Therefore the powers are not distinguished according to the difference of their objects.

  On the contrary, Things that are subsequent are distinguished by what precedes. But the Philosopher says (De Anima ii, 4) that "acts and operations precede the powers according to reason; and these again are preceded by their opposites," that is their objects. Therefore the powers are distinguished according to their acts and objects.

  I answer that, A power as such is directed to an act. Wherefore we seek to know the nature of a power from the act to which it is directed, and consequently the nature of a power is diversified, as the nature of the act is diversified. Now the nature of an act is diversified according to the various natures of the objects. For every act is either of an active power or of a passive power. Now, the object is to the act of a passive power, as the principle and moving cause: for color is the principle of vision, inasmuch as it moves the sight. On the other hand, to the act of an active power the object is a term and end; as the object of the power of growth is perfect quantity, which is the end of growth. Now, from these two things an act receives its species, namely, from its principle, or from its end or term; for the act of heating differs from the act of cooling, in this, that the former proceeds from something hot, which is the active principle, to heat; the latter from something cold, which is the active principle, to cold. Therefore the powers are of necessity distinguished by their acts and objects.

   Nevertheless, we must observe that things which are accidental do not change the species. For since to be colored is accidental to an animal, its species is not changed by a difference of color, but by a difference in that which belongs to the nature of an animal, that is to say, by a difference in the sensitive soul, which is sometimes rational, and sometimes otherwise. Hence "rational" and "irrational" are differences dividing animal, constituting its various species. In like manner therefore, not any variety of objects diversifies the powers of the soul, but a difference in that to which the power of its very nature is directed. Thus the senses of their very nature are directed to the passive quality which of itself is divided into color, sound, and the like, and therefore there is one sensitive power with regard to color, namely, the sight, and another with regard to sound, namely, hearing. But it is accidental to a passive quality, for instance, to something colored, to be a musician or a grammarian, great or small, a man or a stone. Therefore by reason of such differences the powers of the soul are not distinct.

  Reply to Objection 1: Act, though subsequent in existence to power, is, nevertheless, prior to it in intention and logically; as the end is with regard to the agent. And the object, although extrinsic, is, nevertheless, the principle or end of the action; and those conditions which are intrinsic to a thing, are proportionate to its principle and end.

  Reply to Objection 2: If any power were to have one of two contraries as such for its object, the other contrary would belong to another power. But the power of the soul does not regard the nature of the contrary as such, but rather the common aspect of both contraries; as sight does not regard white as such, but as color. This is because of two contraries one, in a manner, includes the idea of the other, since they are to one another as perfect and imperfect.

  Reply to Objection 3: Nothing prevents things which coincide in subject, from being considered under different aspects; therefore they can belong to various powers of the soul.

  Reply to Objection 4: The higher power of itself regards a more universal formality of the object than the lower power; because the higher a power is, to a greater number of things does it extend. Therefore many things are combined in the one formality of the object, which the higher power considers of itself; while they differ in the formalities regarded by the lower powers of themselves. Thus it is that various objects belong to various lower powers; which objects, however, are subject to one higher power.
 
Article: 4

Whether among the powers of the soul there is order?

  Objection 1: It would seem that there is no order among the powers of the soul. For in those things which come under one division, there is no before and after, but all are naturally simultaneous. But the powers of the soul are contradistinguished from one another. Therefore there is no order among them.

  Objection 2: Further, the powers of the soul are referred to their objects and to the soul itself. On the part of the soul, there is not order among them, because the soul is one. In like manner the objects are various and dissimilar, as color and sound. Therefore there is no order among the powers of the soul.

  Objection 3: Further, where there is order among powers, we find that the operation of one depends on the operation of another. But the action of one power of the soul does not depend on that of another; for sight can act independently of hearing, and conversely. Therefore there is no order among the powers of the soul.

  On the contrary, The Philosopher (De Anima ii, 3) compares the parts or powers of the soul to figures. But figures have an order among themselves. Therefore the powers of the soul have order.

  I answer that, Since the soul is one, and the powers are many; and since a number of things that proceed from one must proceed in a certain order; there must be some order among the powers of the soul. Accordingly we may observe a triple order among them, two of which correspond to the dependence of one power on another; while the third is taken from the order of the objects. Now the dependence of one power on another can be taken in two ways; according to the order of nature, forasmuch as perfect things are by their nature prior to imperfect things; and according to the order of generation and time; forasmuch as from being imperfect, a thing comes to be perfect. Thus, according to the first kind of order among the powers, the intellectual powers are prior to the sensitive powers; wherefore they direct them and command them. Likewise the sensitive powers are prior in this order to the powers of the nutritive soul.

   In the second kind of order, it is the other way about. For the powers of the nutritive soul are prior by way of generation to the powers of the sensitive soul; for which, therefore, they prepare the body. The same is to be said of the sensitive powers with regard to the intellectual. But in the third kind of order, certain sensitive powers are ordered among themselves, namely, sight, hearing, and smelling. For the visible naturally comes first; since it is common to higher and lower bodies. But sound is audible in the air, which is naturally prior to the mingling of elements, of which smell is the result.

  Reply to Objection 1: The species of a given genus are to one another as before and after, like numbers and figures, if considered in their nature; although they may be said to be simultaneous, according as they receive the predication of the common genus.

  Reply to Objection 2: This order among the powers of the soul is both on the part of the soul (which, though it be one according to its essence, has a certain aptitude to various acts in a certain order) and on the part of the objects, and furthermore on the part of the acts, as we have said above.

  Reply to Objection 3: This argument is verified as regards those powers among which order of the third kind exists. Those powers among which the two other kinds of order exist are such that the action of one depends on another.

Article: 5 

Whether all the powers of the soul are in the soul as their subject?

  Objection 1: It would seem that all the powers of the soul are in the soul as their subject. For as the powers of the body are to the body; so are the powers of the soul to the soul. But the body is the subject of the corporeal powers. Therefore the soul is the subject of the powers of the soul.

  Objection 2: Further, the operations of the powers of the soul are attributed to the body by reason of the soul; because, as the Philosopher says (De Anima ii, 2), "The soul is that by which we sense and understand primarily." But the natural principles of the operations of the soul are the powers. Therefore the powers are primarily in the soul.

  Objection 3: Further, Augustine says (Gen. ad lit. xii, 7,24) that the soul senses certain things, not through the body, in fact, without the body, as fear and such like; and some things through the body. But if the sensitive powers were not in the soul alone as their subject, the soul could not sense anything without the body. Therefore the soul is the subject of the sensitive powers; and for a similar reason, of all the other powers.

  On the contrary, The Philosopher says (De Somno et Vigilia i) that "sensation belongs neither to the soul, nor to the body, but to the composite." Therefore the sensitive power is in "the composite" as its subject. Therefore the soul alone is not the subject of all the powers.

  I answer that, The subject of operative power is that which is able to operate, for every accident denominates its proper subject. Now the same is that which is able to operate, and that which does operate. Wherefore the "subject of power" is of necessity "the subject of operation," as again the Philosopher says in the beginning of De Somno et Vigilia. Now, it is clear from what we have said above (Question [75], Articles [2],3; Question [76], Article [1], ad 1), that some operations of the soul are performed without a corporeal organ, as understanding and will. Hence the powers of these operations are in the soul as their subject. But some operations of the soul are performed by means of corporeal organs; as sight by the eye, and hearing by the ear. And so it is with all the other operations of the nutritive and sensitive parts. Therefore the powers which are the principles of these operations have their subject in the composite, and not in the soul alone.

  Reply to Objection 1: All the powers are said to belong to the soul, not as their subject, but as their principle; because it is by the soul that the composite has the power to perform such operations.

  Reply to Objection 2: All such powers are primarily in the soul, as compared to the composite; not as in their subject, but as in their principle.

  Reply to Objection 3: Plato's opinion was that sensation is an operation proper to the soul, just as understanding is. Now in many things relating to Philosophy Augustine makes use of the opinions of Plato, not asserting them as true, but relating them. However, as far as the present question is concerned, when it is said that the soul senses some things with the body, and some without the body, this can be taken in two ways. Firstly, the words "with the body or without the body" may determine the act of sense in its mode of proceeding from the sentient. Thus the soul senses nothing without the body, because the action of sensation cannot proceed from the soul except by a corporeal organ. Secondly, they may be understood as determining the act of sense on the part of the object sensed. Thus the soul senses some things with the body, that is, things existing in the body, as when it feels a wound or something of that sort; while it senses some things without the body, that is, which do not exist in the body, but only in the apprehension of the soul, as when it feels sad or joyful on hearing something.
 
Article: 6 

Whether the powers of the soul flow from its essence?

  Objection 1: It would seem that the powers of the soul do not flow from its essence. For different things do not proceed from one simple thing. But the essence of the soul is one and simple. Since, therefore, the powers of the soul are many and various, they cannot proceed from its essence.

  Objection 2: Further, that from which a thing proceeds is its cause. But the essence of the soul cannot be said to be the cause of the powers; as is clear if one considers the different kinds of causes. Therefore the powers of the soul do not flow from its essence.

  Objection 3: Further, emanation involves some sort of movement. But nothing is moved by itself, as the Philosopher proves (Phys. vii, 1,2); except, perhaps, by reason of a part of itself, as an animal is said to be moved by itself, because one part thereof moves and another is moved. Neither is the soul moved, as the Philosopher proves (De Anima i, 4). Therefore the soul does not produce its powers within itself.

  On the contrary, The powers of the soul are its natural properties. But the subject is the cause of its proper accidents; whence also it is included in the definition of accident, as is clear from Metaph. vii (Did. vi, 4). Therefore the powers of the soul proceed from its essence as their cause.

  I answer that, The substantial and the accidental form partly agree and partly differ. They agree in this, that each is an act; and that by each of them something is after a manner actual. They differ, however, in two respects. First, because the substantial form makes a thing to exist absolutely, and its subject is something purely potential. But the accidental form does not make a thing to exist absolutely but to be such, or so great, or in some particular condition; for its subject is an actual being. Hence it is clear that actuality is observed in the substantial form prior to its being observed in the subject: and since that which is first in a genus is the cause in that genus, the substantial form causes existence in its subject. On the other hand, actuality is observed in the subject of the accidental form prior to its being observed in the accidental form; wherefore the actuality of the accidental form is caused by the actuality of the subject. So the subject, forasmuch as it is in potentiality, is receptive of the accidental form: but forasmuch as it is in act, it produces it. This I say of the proper and "per se" accident; for with regard to the extraneous accident, the subject is receptive only, the accident being caused by an extrinsic agent. Secondly, substantial and accidental forms differ, because, since that which is the less principal exists for the sake of that which is the more principal, matter therefore exists on account of the substantial form; while on the contrary, the accidental form exists on account of the completeness of the subject.

   Now it is clear, from what has been said (Article [5]), that either the subject of the soul's powers is the soul itself alone, which can be the subject of an accident, forasmuch as it has something of potentiality, as we have said above (Article [1], ad 6); or else this subject is the composite. Now the composite is actual by the soul. Whence it is clear that all the powers of the soul, whether their subject be the soul alone, or the composite, flow from the essence of the soul, as from their principle; because it has already been said that the accident is caused by the subject according as it is actual, and is received into it according as it is in potentiality.

  Reply to Objection 1: From one simple thing many things may proceed naturally, in a certain order; or again if there be diversity of recipients. Thus, from the one essence of the soul many and various powers proceed; both because order exists among these powers; and also by reason of the diversity of the corporeal organs.

  Reply to Objection 2: The subject is both the final cause, and in a way the active cause, of its proper accident. It is also as it were the material cause, inasmuch as it is receptive of the accident. From this we may gather that the essence of the soul is the cause of all its powers, as their end, and as their active principle; and of some as receptive thereof.

  Reply to Objection 3: The emanation of proper accidents from their subject is not by way of transmutation, but by a certain natural resultance; thus one thing results naturally from another, as color from light.
 
Article: 7 

Whether one power of the soul arises from another?

  Objection 1: It would seem that one power of the soul does not arise from another. For if several things arise together, one of them does not arise from another. But all the powers of the soul are created at the same time with the soul. Therefore one of them does not arise from another.

  Objection 2: Further, the power of the soul arises from the soul as an accident from the subject. But one power of the soul cannot be the subject of another; because nothing is the accident of an accident. Therefore one power does not arise from another.

  Objection 3: Further, one opposite does not arise from the other opposite; but everything arises from that which is like it in species. Now the powers of the soul are oppositely divided, as various species. Therefore one of them does not proceed from another.

  On the contrary, Powers are known by their actions. But the action of one power is caused by the action of another power, as the action of the imagination by the action of the senses. Therefore one power of the soul is caused by another.

  I answer that, In those things which proceed from one according to a natural order, as the first is the cause of all, so that which is nearer to the first is, in a way, the cause of those which are more remote. Now it has been shown above (Article [4]) that among the powers of the soul there are several kinds of order. Therefore one power of the soul proceeds from the essence of the soul by the medium of another. But since the essence of the soul is compared to the powers both as a principle active and final, and as a receptive principle, either separately by itself, or together with the body; and since the agent and the end are more perfect, while the receptive principle, as such, is less perfect; it follows that those powers of the soul which precede the others, in the order of perfection and nature, are the principles of the others, after the manner of the end and active principle. For we see that the senses are for the sake of the intelligence, and not the other way about. The senses, moreover, are a certain imperfect participation of the intelligence; wherefore, according to their natural origin, they proceed from the intelligence as the imperfect from the perfect. But considered as receptive principles, the more perfect powers are principles with regard to the others; thus the soul, according as it has the sensitive power, is considered as the subject, and as something material with regard to the intelligence. On this account, the more imperfect powers precede the others in the order of generation, for the animal is generated before the man.

  Reply to Objection 1: As the power of the soul flows from the essence, not by a transmutation, but by a certain natural resultance, and is simultaneous with the soul, so is it the case with one power as regards another.

  Reply to Objection 2: An accident cannot of itself be the subject of an accident; but one accident is received prior to another into substance, as quantity prior to quality. In this sense one accident is said to be the subject of another; as surface is of color, inasmuch as substance receives an accident through the means of another. The same thing may be said of the powers of the soul.

  Reply to Objection 3: The powers of the soul are opposed to one another, as perfect and imperfect; as also are the species of numbers and figures. But this opposition does not prevent the origin of one from another, because imperfect things naturally proceed from perfect things.
 
Article: 8 

Whether all the powers remain in the soul when separated from the body?

  Objection 1: It would seem that all the powers of the soul remain in the soul separated from the body. For we read in the book De Spiritu et Anima that "the soul withdraws from the body, taking with itself sense and imagination, reason and intelligence, concupiscibility and irascibility."

  Objection 2: Further, the powers of the soul are its natural properties. But properties are always in that to which they belong; and are never separated from it. Therefore the powers of the soul are in it even after death.

  Objection 3: Further, the powers even of the sensitive soul are not weakened when the body becomes weak; because, as the Philosopher says (De Anima i, 4), "If an old man were given the eye of a young man, he would see even as well as a young man." But weakness is the road to corruption. Therefore the powers of the soul are not corrupted when the body is corrupted, but remain in the separated soul.

  Objection 4: Further, memory is a power of the sensitive soul, as the Philosopher proves (De Memor. et Remin. 1). But memory remains in the separated soul; for it was said to the rich glutton whose soul was in hell: "Remember that thou didst receive good things during thy lifetime" (Lk. 16:25). Therefore memory remains in the separated soul; and consequently the other powers of the sensitive part.

  Objection 5: Further, joy and sorrow are in the concupiscible part, which is a power of the sensitive soul. But it is clear that separate souls grieve or rejoice at the pains or rewards which they receive. Therefore the concupiscible power remains in the separate soul.

  Objection 6: Further, Augustine says (Gen. ad lit. xii, 32) that, as the soul, when the body lies senseless, yet not quite dead, sees some things by imaginary vision; so also when by death the soul is quite separate from the body. But the imagination is a power of the sensitive part. Therefore the power of the sensitive part remains in the separate soul; and consequently all the other powers.

  On the contrary, It is said (De Eccl. Dogm. xix) that "of two substances only does man consist; the soul with its reason, and the body with its senses." Therefore the body being dead, the sensitive powers do not remain.

  I answer that, As we have said already (Articles [5],6,7), all the powers of the soul belong to the soul alone as their principle. But some powers belong to the soul alone as their subject; as the intelligence and the will. These powers must remain in the soul, after the destruction of the body. But other powers are subjected in the composite; as all the powers of the sensitive and nutritive parts. Now accidents cannot remain after the destruction of the subject. Wherefore, the composite being destroyed, such powers do not remain actually; but they remain virtually in the soul, as in their principle or root.

   So it is false that, as some say, these powers remain in the soul even after the corruption of the body. It is much more false that, as they say also, the acts of these powers remain in the separate soul; because these powers have no act apart from the corporeal organ.

  Reply to Objection 1: That book has no authority, and so what is there written can be despised with the same facility as it was said; although we may say that the soul takes with itself these powers, not actually but virtually.

  Reply to Objection 2: These powers, which we say do not actually remain in the separate soul, are not the properties of the soul alone, but of the composite.

  Reply to Objection 3: These powers are said not to be weakened when the body becomes weak, because the soul remains unchangeable, and is the virtual principle of these powers.

  Reply to Objection 4: The recollection spoken of there is to be taken in the same way as Augustine (De Trin. x, 11; xiv, 7) places memory in the mind; not as a part of the sensitive soul.

  Reply to Objection 5: In the separate soul, sorrow and joy are not in the sensitive, but in the intellectual appetite, as in the angels.

  Reply to Objection 6: Augustine in that passage is speaking as inquiring, not as asserting. Wherefore he retracted some things which he had said there (Retrac. ii, 24).

Question: 78 OF THE SPECIFIC POWERS OF THE SOUL (FOUR ARTICLES)

   We next treat of the powers of the soul specifically. The theologian, however, has only to inquire specifically concerning the intellectual and appetitive powers, in which the virtues reside. And since the knowledge of these powers depends to a certain extent on the other powers, our consideration of the powers of the soul taken specifically will be divided into three parts: first, we shall consider those powers which are a preamble to the intellect; secondly, the intellectual powers; thirdly, the appetitive powers.

   Under the first head there are four points of inquiry:

    (1) The powers of the soul considered generally;

    (2) The various species of the vegetative part;

    (3) The exterior senses;

    (4) The interior senses.

Article: 1 

Whether there are to be distinguished five genera of powers in the soul?

  Objection 1: It would seem that there are not to be distinguished five genera of powers in the soul---namely, vegetative, sensitive, appetitive, locomotive, and intellectual. For the powers of the soul are called its parts. But only three parts of the soul are commonly assigned---namely, the vegetative soul, the sensitive soul, and the rational soul. Therefore there are only three genera of powers in the soul, and not five.

  Objection 2: Further, the powers of the soul are the principles of its vital operations. Now, in four ways is a thing said to live. For the Philosopher says (De Anima ii, 2): "In several ways a thing is said to live, and even if only one of these is present, the thing is said to live; as intellect and sense, local movement and rest, and lastly, movement of decrease and increase due to nourishment." Therefore there are only four genera of powers of the soul, as the appetitive is excluded.

  Objection 3: Further, a special kind of soul ought not to be assigned as regards what is common to all the powers. Now desire is common to each power of the soul. For sight desires an appropriate visible object; whence we read (Ecclus. 40:22): "The eye desireth favor and beauty, but more than these green sown fields." In the same way every other power desires its appropriate object. Therefore the appetitive power should not be made a special genus of the powers of the soul.

  Objection 4: Further, the moving principle in animals is sense, intellect or appetite, as the Philosopher says (De Anima iii, 10). Therefore the motive power should not be added to the above as a special genus of soul.

  On the contrary, The Philosopher says (De Anima ii, 3), "The powers are the vegetative, the sensitive, the appetitive, the locomotion, and the intellectual."

  I answer that, There are five genera of powers of the soul, as above numbered. Of these, three are called souls, and four are called modes of living. The reason of this diversity lies in the various souls being distinguished accordingly as the operation of the soul transcends the operation of the corporeal nature in various ways; for the whole corporeal nature is subject to the soul, and is related to it as its matter and instrument. There exists, therefore, an operation of the soul which so far exceeds the corporeal nature that it is not even performed by any corporeal organ; and such is the operation of the "rational soul." Below this, there is another operation of the soul, which is indeed performed through a corporeal organ, but not through a corporeal quality, and this is the operation of the "sensitive soul"; for though hot and cold, wet and dry, and other such corporeal qualities are required for the work of the senses, yet they are not required in such a way that the operation of the senses takes place by virtue of such qualities; but only for the proper disposition of the organ. The lowest of the operations of the soul is that which is performed by a corporeal organ, and by virtue of a corporeal quality. Yet this transcends the operation of the corporeal nature; because the movements of bodies are caused by an extrinsic principle, while these operations are from an intrinsic principle; for this is common to all the operations of the soul; since every animate thing, in some way, moves itself. Such is the operation of the "vegetative soul"; for digestion, and what follows, is caused instrumentally by the action of heat, as the Philosopher says (De Anima ii, 4).

   Now the powers of the soul are distinguished generically by their objects. For the higher a power is, the more universal is the object to which it extends, as we have said above (Question [77], Article [3], ad 4). But the object of the soul's operation may be considered in a triple order. For in the soul there is a power the object of which is only the body that is united to that soul; the powers of this genus are called "vegetative" for the vegetative power acts only on the body to which the soul is united. There is another genus in the powers of the soul, which genus regards a more universal object---namely, every sensible body, not only the body to which the soul is united. And there is yet another genus in the powers of the soul, which genus regards a still more universal object---namely, not only the sensible body, but all being in universal. Wherefore it is evident that the latter two genera of the soul's powers have an operation in regard not merely to that which is united to them, but also to something extrinsic. Now, since whatever operates must in some way be united to the object about which it operates, it follows of necessity that this something extrinsic, which is the object of the soul's operation, must be related to the soul in a twofold manner. First, inasmuch as this something extrinsic has a natural aptitude to be united to the soul, and to be by its likeness in the soul. In this way there are two kinds of powers ---namely, the "sensitive" in regard to the less common object---the sensible body; and the "intellectual," in regard to the most common object---universal being. Secondly, forasmuch as the soul itself has an inclination and tendency to the something extrinsic. And in this way there are again two kinds of powers in the soul: one---the "appetitive"---in respect of which the soul is referred to something extrinsic as to an end, which is first in the intention; the other---the "locomotive" power---in respect of which the soul is referred to something extrinsic as to the term of its operation and movement; for every animal is moved for the purpose of realizing its desires and intentions.

   The modes of living are distinguished according to the degrees of living things. There are some living things in which there exists only vegetative power, as the plants. There are others in which with the vegetative there exists also the sensitive, but not the locomotive power; such as immovable animals, as shellfish. There are others which besides this have locomotive powers, as perfect animals, which require many things for their life, and consequently movement to seek necessaries of life from a distance. And there are some living things which with these have intellectual power---namely, men. But the appetitive power does not constitute a degree of living things; because wherever there is sense there is also appetite (De Anima ii, 3).

   Thus the first two objectives are hereby solved.

  Reply to Objection 3: The "natural appetite" is that inclination which each thing has, of its own nature, for something; wherefore by its natural appetite each power desires something suitable to itself. But the "animal appetite" results from the form apprehended; this sort of appetite requires a special power of the soul---mere apprehension does not suffice. For a thing is desired as it exists in its own nature, whereas in the apprehensive power it exists not according to its own nature, but according to its likeness. Whence it is clear that sight desires naturally a visible object for the purpose of its act only---namely, for the purpose of seeing; but the animal by the appetitive power desires the thing seen, not merely for the purpose of seeing it, but also for other purposes. But if the soul did not require things perceived by the senses, except on account of the actions of the senses, that is, for the purpose of sensing them; there would be no need for a special genus of appetitive powers, since the natural appetite of the powers would suffice.

  Reply to Objection 4: Although sense and appetite are principles of movement in perfect animals, yet sense and appetite, as such, are not sufficient to cause movement, unless another power be added to them; for immovable animals have sense and appetite, and yet they have not the power of motion. Now this motive power is not only in the appetite and sense as commanding the movement, but also in the parts of the body, to make them obey the appetite of the soul which moves them. Of this we have a sign in the fact that when the members are deprived of their natural disposition, they do not move in obedience to the appetite.
 
Article: 2 

Whether the parts of the vegetative soul are fittingly described as the nutritive, augmentative, and generative?

  Objection 1: It would seem that the parts of the vegetative soul are not fittingly described---namely, the nutritive, augmentative, and generative. For these are called "natural" forces. But the powers of the soul are above the natural forces. Therefore we should not class the above forces as powers of the soul.

  Objection 2: Further, we should not assign a particular power of the soul to that which is common to living and non-living things. But generation is common to all things that can be generated and corrupted, whether living or not living. Therefore the generative force should not be classed as a power of the soul.

  Objection 3: Further, the soul is more powerful than the body. But the body by the same force gives species and quantity; much more, therefore, does the soul. Therefore the augmentative power of the soul is not distinct from the generative power.

  Objection 4: Further, everything is preserved in being by that whereby it exists. But the generative power is that whereby a living thing exists. Therefore by the same power the living thing is preserved. Now the nutritive force is directed to the preservation of the living thing (De Anima ii, 4), being "a power which is capable of preserving whatever receives it." Therefore we should not distinguish the nutritive power from the generative.

  On the contrary, The Philosopher says (De Anima ii, 2,4) that the operations of this soul are "generation, the use of food," and (cf. De Anima iii, 9) "growth."

  I answer that, The vegetative part has three powers. For the vegetative part, as we have said (Article [1]), has for its object the body itself, living by the soul; for which body a triple operation of the soul is required. One is whereby it acquires existence, and to this is directed the "generative" power. Another is whereby the living body acquires its due quantity; to this is directed the "augmentative" power. Another is whereby the body of a living thing is preserved in its existence and in its due quantity; to this is directed the "nutritive" power.

   We must, however, observe a difference among these powers. The nutritive and the augmentative have their effect where they exist, since the body itself united to the soul grows and is preserved by the augmentative and nutritive powers which exist in one and the same soul. But the generative power has its effect, not in one and the same body but in another; for a thing cannot generate itself. Therefore the generative power, in a way, approaches to the dignity of the sensitive soul, which has an operation extending to extrinsic things, although in a more excellent and more universal manner; for that which is highest in an inferior nature approaches to that which is lowest in the higher nature, as is made clear by Dionysius (Div. Nom. vii). Therefore, of these three powers, the generative has the greater finality, nobility, and perfection, as the Philosopher says (De Anima ii, 4), for it belongs to a thing which is already perfect to "produce another like unto itself." And the generative power is served by the augmentative and nutritive powers; and the augmentative power by the nutritive.

  Reply to Objection 1: Such forces are called natural, both because they produce an effect like that of nature, which also gives existence, quantity and preservation (although the above forces accomplish these things in a more perfect way); and because those forces perform their actions instrumentally, through the active and passive qualities, which are the principles of natural actions.

  Reply to Objection 2: Generation of inanimate things is entirely from an extrinsic source; whereas the generation of living things is in a higher way, through something in the living thing itself, which is the semen containing the principle productive of the body. Therefore there must be in the living thing a power that prepares this semen; and this is the generative power.

  Reply to Objection 3: Since the generation of living things is from a semen, it is necessary that in the beginning an animal of small size be generated. For this reason it must have a power in the soul, whereby it is brought to its appropriate size. But the inanimate body is generated from determinate matter by an extrinsic agent; therefore it receives at once its nature and its quantity, according to the condition of the matter.

  Reply to Objection 4: As we have said above (Article [1]), the operation of the vegetative principle is performed by means of heat, the property of which is to consume humidity. Therefore, in order to restore the humidity thus lost, the nutritive power is required, whereby the food is changed into the substance of the body. This is also necessary for the action of the augmentative and generative powers.
 
Article: 3 

Whether the five exterior senses are properly distinguished?

  Objection 1: It would seem inaccurate to distinguish five exterior senses. But there are many kinds of accidents. Therefore, as powers are distinguished by their objects, it seems that the senses are multiplied according to the number of the kinds of accidents.

  Objection 2: Further, magnitude and shape, and other things which are called "common sensibles," are "not sensibles by accident," but are contradistinguished from them by the Philosopher (De Anima ii, 6). Now the diversity of objects, as such, diversifies the powers. Since, therefore, magnitude and shape are further from color than sound is, it seems that there is much more need for another sensitive power than can grasp magnitude or shape than for that which grasps color or sound.

  Objection 3: Further, one sense regards one contrariety; as sight regards white and black. But the sense of touch grasps several contraries; such as hot or cold, damp or dry, and suchlike. Therefore it is not a single sense but several. Therefore there are more than five senses.

  Objection 4: Further, a species is not divided against its genus. But taste is a kind of touch. Therefore it should not be classed as a distinct sense of touch.

  On the contrary, The Philosopher says (De Anima iii, 1): "There is no other besides the five senses."

  I answer that, The reason of the distinction and number of the senses has been assigned by some to the organs in which one or other of the elements preponderate, as water, air, or the like. By others it has been assigned to the medium, which is either in conjunction or extrinsic and is either water or air, or such like. Others have ascribed it to the various natures of the sensible qualities, according as such quality belongs to a simple body or results from complexity. But none of these explanations is apt. For the powers are not for the organs, but the organs for the powers; wherefore there are not various powers for the reason that there are various organs; on the contrary, for this has nature provided a variety of organs, that they might be adapted to various powers. In the same way nature provided various mediums for the various senses, according to the convenience of the acts of the powers. And to be cognizant of the natures of sensible qualities does not pertain to the senses, but to the intellect.

   The reason of the number and distinction of the exterior senses must therefore be ascribed to that which belongs to the senses properly and "per se." Now, sense is a passive power, and is naturally immuted by the exterior sensible. Wherefore the exterior cause of such immutation is what is "per se" perceived by the sense, and according to the diversity of that exterior cause are the sensitive powers diversified.

   Now, immutation is of two kinds, one natural, the other spiritual. Natural immutation takes place by the form of the immuter being received according to its natural existence, into the thing immuted, as heat is received into the thing heated. Whereas spiritual immutation takes place by the form of the immuter being received, according to a spiritual mode of existence, into the thing immuted, as the form of color is received into the pupil which does not thereby become colored. Now, for the operation of the senses, a spiritual immutation is required, whereby an intention of the sensible form is effected in the sensile organ. Otherwise, if a natural immutation alone sufficed for the sense's action, all natural bodies would feel when they undergo alteration.

   But in some senses we find spiritual immutation only, as in "sight" while in others we find not only spiritual but also a natural immutation; either on the part of the object only, or likewise on the part of the organ. On the part of the object we find natural immutation, as to place, in sound which is the object of "hearing"; for sound is caused by percussion and commotion of air: and we find natural immutation by alteration, in odor which is the object of "smelling"; for in order to exhale an odor, a body must be in a measure affected by heat. On the part of an organ, natural immutation takes place in "touch" and "taste"; for the hand that touches something hot becomes hot, while the tongue is moistened by the humidity of the flavored morsel. But the organs of smelling and hearing are not affected in their respective operations by any natural immutation unless indirectly.

   Now, the sight, which is without natural immutation either in its organ or in its object, is the most spiritual, the most perfect, and the most universal of all the senses. After this comes the hearing and then the smell, which require a natural immutation on the part of the object; while local motion is more perfect than, and naturally prior to, the motion of alteration, as the Philosopher proves (Phys. viii, 7). Touch and taste are the most material of all: of the distinction of which we shall speak later on (ad 3,4). Hence it is that the three other senses are not exercised through a medium united to them, to obviate any natural immutation in their organ; as happens as regards these two senses.

  Reply to Objection 1: Not every accident has in itself a power of immutation but only qualities of the third species, which are the principles of alteration: therefore only suchlike qualities are the objects of the senses; because "the senses are affected by the same things whereby inanimate bodies are affected," as stated in Phys. vii, 2.

  Reply to Objection 2: Size, shape, and the like, which are called "common sensibles," are midway between "accidental sensibles" and "proper sensibles," which are the objects of the senses. For the proper sensibles first, and of their very nature, affect the senses; since they are qualities that cause alteration. But the common sensibles are all reducible to quantity. As to size and number, it is clear that they are species of quantity. Shape is a quality about quantity. Shape is a quality about quantity, since the notion of shape consists of fixing the bounds of magnitude. Movement and rest are sensed according as the subject is affected in one or more ways in the magnitude of the subject or of its local distance, as in the movement of growth or of locomotion, or again, according as it is affected in some sensible qualities, as in the movement of alteration; and thus to sense movement and rest is, in a way, to sense one thing and many. Now quantity is the proximate subject of the qualities that cause alteration, as surface is of color. Therefore the common sensibles do not move the senses first and of their own nature, but by reason of the sensible quality; as the surface by reason of color. Yet they are not accidental sensibles, for they produce a certain variety in the immutation of the senses. For sense is immuted differently by a large and by a small surface: since whiteness itself is said to be great or small, and therefore it is divided according to its proper subject.

  Reply to Objection 3: As the Philosopher seems to say (De Anima ii, 11), the sense of touch is generically one, but is divided into several specific senses, and for this reason it extends to various contrarieties; which senses, however, are not separate from one another in their organ, but are spread throughout the whole body, so that their distinction is not evident. But taste, which perceives the sweet and the bitter, accompanies touch in the tongue, but not in the whole body; so it is easily distinguished from touch. We might also say that all those contrarieties agree, each in some proximate genus, and all in a common genus, which is the common and formal object of touch. Such common genus is, however, unnamed, just as the proximate genus of hot and cold is unnamed.

  Reply to Objection 4: The sense of taste, according to a saying of the Philosopher (De Anima ii, 9), is a kind of touch existing in the tongue only. It is not distinct from touch in general, but only from the species of touch distributed in the body. But if touch is one sense only, on account of the common formality of its object: we must say that taste is distinguished from touch by reason of a different formality of immutation. For touch involves a natural, and not only a spiritual, immutation in its organ, by reason of the quality which is its proper object. But the organ of taste is not necessarily immuted by a natural immutation by reason of the quality which is its proper object, so that the tongue itself becomes sweet and bitter: but by reason of a quality which is a preamble to, and on which is based, the flavor, which quality is moisture, the object of touch.
 
Article: 4

Whether the interior senses are suitably distinguished?

  Objection 1: It would seem that the interior senses are not suitably distinguished. For the common is not divided against the proper. Therefore the common sense should not be numbered among the interior sensitive powers, in addition to the proper exterior senses.

  Objection 2: Further, there is no need to assign an interior power of apprehension when the proper and exterior sense suffices. But the proper and exterior senses suffice for us to judge of sensible things; for each sense judges of its proper object. In like manner they seem to suffice for the perception of their own actions; for since the action of the sense is, in a way, between the power and its object, it seems that sight must be much more able to perceive its own vision, as being nearer to it, than the color; and in like manner with the other senses. Therefore for this there is no need to assign an interior power, called the common sense.

  Objection 3: Further, according to the Philosopher (De Memor. et Remin. i), the imagination and the memory are passions of the "first sensitive." But passion is not divided against its subject. Therefore memory and imagination should not be assigned as powers distinct from the senses.

  Objection 4: Further, the intellect depends on the senses less than any power of the sensitive part. But the intellect knows nothing but what it receives from the senses; whence we read (Poster. i, 8), that "those who lack one sense lack one kind of knowledge." Therefore much less should we assign to the sensitive part a power, which they call the "estimative" power, for the perception of intentions which the sense does not perceive.

  Objection 5: Further, the action of the cogitative power, which consists in comparing, adding and dividing, and the action of the reminiscence, which consists in the use of a kind of syllogism for the sake of inquiry, is not less distant from the actions of the estimative and memorative powers, than the action of the estimative is from the action of the imagination. Therefore either we must add the cognitive and reminiscitive to the estimative and memorative powers, or the estimative and memorative powers should not be made distinct from the imagination.

  Objection 6: Further, Augustine (Gen. ad lit. xii, 6,7,24) describes three kinds of vision; namely, corporeal, which is the action of the sense; spiritual, which is an action of the imagination or phantasy; and intellectual, which is an action of the intellect. Therefore there is no interior power between the sense and intellect, besides the imagination.

  On the contrary, Avicenna (De Anima iv, 1) assigns five interior sensitive powers; namely, "common sense, phantasy, imagination, and the estimative and memorative powers."

  I answer that, As nature does not fail in necessary things, there must needs be as many actions of the sensitive soul as may suffice for the life of a perfect animal. If any of these actions cannot be reduced to the same one principle, they must be assigned to diverse powers; since a power of the soul is nothing else than the proximate principle of the soul's operation.

   Now we must observe that for the life of a perfect animal, the animal should apprehend a thing not only at the actual time of sensation, but also when it is absent. Otherwise, since animal motion and action follow apprehension, an animal would not be moved to seek something absent: the contrary of which we may observe specially in perfect animals, which are moved by progression, for they are moved towards something apprehended and absent. Therefore an animal through the sensitive soul must not only receive the species of sensible things, when it is actually affected by them, but it must also retain and preserve them. Now to receive and retain are, in corporeal things, reduced to diverse principles; for moist things are apt to receive, but retain with difficulty, while it is the reverse with dry things. Wherefore, since the sensitive power is the act of a corporeal organ, it follows that the power which receives the species of sensible things must be distinct from the power which preserves them.

   Again we must observe that if an animal were moved by pleasing and disagreeable things only as affecting the sense, there would be no need to suppose that an animal has a power besides the apprehension of those forms which the senses perceive, and in which the animal takes pleasure, or from which it shrinks with horror. But the animal needs to seek or to avoid certain things, not only because they are pleasing or otherwise to the senses, but also on account of other advantages and uses, or disadvantages: just as the sheep runs away when it sees a wolf, not on account of its color or shape, but as a natural enemy: and again a bird gathers together straws, not because they are pleasant to the sense, but because they are useful for building its nest. Animals, therefore, need to perceive such intentions, which the exterior sense does not perceive. And some distinct principle is necessary for this; since the perception of sensible forms comes by an immutation caused by the sensible, which is not the case with the perception of those intentions.

   Thus, therefore, for the reception of sensible forms, the "proper sense" and the "common sense" are appointed, and of their distinction we shall speak farther on (ad 1,2). But for the retention and preservation of these forms, the "phantasy" or "imagination" is appointed; which are the same, for phantasy or imagination is as it were a storehouse of forms received through the senses. Furthermore, for the apprehension of intentions which are not received through the senses, the "estimative" power is appointed: and for the preservation thereof, the "memorative" power, which is a storehouse of such-like intentions. A sign of which we have in the fact that the principle of memory in animals is found in some such intention, for instance, that something is harmful or otherwise. And the very formality of the past, which memory observes, is to be reckoned among these intentions.

   Now, we must observe that as to sensible forms there is no difference between man and other animals; for they are similarly immuted by the extrinsic sensible. But there is a difference as to the above intentions: for other animals perceive these intentions only by some natural instinct, while man perceives them by means of coalition of ideas. Therefore the power by which in other animals is called the natural estimative, in man is called the "cogitative," which by some sort of collation discovers these intentions. Wherefore it is also called the "particular reason," to which medical men assign a certain particular organ, namely, the middle part of the head: for it compares individual intentions, just as the intellectual reason compares universal intentions. As to the memorative power, man has not only memory, as other animals have in the sudden recollection of the past; but also "reminiscence" by syllogistically, as it were, seeking for a recollection of the past by the application of individual intentions. Avicenna, however, assigns between the estimative and the imaginative, a fifth power, which combines and divides imaginary forms: as when from the imaginary form of gold, and imaginary form of a mountain, we compose the one form of a golden mountain, which we have never seen. But this operation is not to be found in animals other than man, in whom the imaginative power suffices thereto. To man also does Averroes attribute this action in his book De sensu et sensibilibus (viii). So there is no need to assign more than four interior powers of the sensitive part---namely, the common sense, the imagination, and the estimative and memorative powers.

  Reply to Objection 1: The interior sense is called "common" not by predication, as if it were a genus; but as the common root and principle of the exterior senses.

  Reply to Objection 2: The proper sense judges of the proper sensible by discerning it from other things which come under the same sense; for instance, by discerning white from black or green. But neither sight nor taste can discern white from sweet: because what discerns between two things must know both. Wherefore the discerning judgment must be assigned to the common sense; to which, as to a common term, all apprehensions of the senses must be referred: and by which, again, all the intentions of the senses are perceived; as when someone sees that he sees. For this cannot be done by the proper sense, which only knows the form of the sensible by which it is immuted, in which immutation the action of sight is completed, and from immutation follows another in the common sense which perceives the act of vision.

  Reply to Objection 3: As one power arises from the soul by means of another, as we have seen above (Question [77], Article [7]), so also the soul is the subject of one power through another. In this way the imagination and the memory are called passions of the "first sensitive."

  Reply to Objection 4: Although the operation of the intellect has its origin in the senses: yet, in the thing apprehended through the senses, the intellect knows many things which the senses cannot perceive. In like manner does the estimative power, though in a less perfect manner.

  Reply to Objection 5: The cogitative and memorative powers in man owe their excellence not to that which is proper to the sensitive part; but to a certain affinity and proximity to the universal reason, which, so to speak, overflows into them. Therefore they are not distinct powers, but the same, yet more perfect than in other animals.

  Reply to Objection 6: Augustine calls that vision spiritual which is effected by the images of bodies in the absence of bodies. Whence it is clear that it is common to all interior apprehensions.

Question: 79  OF THE INTELLECTUAL POWERS (THIRTEEN ARTICLES)

   The next question concerns the intellectual powers, under which head there are thirteen points of inquiry:

    (1) Whether the intellect is a power of the soul, or its essence?

    (2) If it be a power, whether it is a passive power?

    (3) If it is a passive power, whether there is an active intellect?

    (4) Whether it is something in the soul?

    (5) Whether the active intellect is one in all?

    (6) Whether memory is in the intellect?

    (7) Whether the memory be distinct from the intellect?

    (8) Whether the reason is a distinct power from the intellect?

    (9) Whether the superior and inferior reason are distinct powers?

    (10) Whether the intelligence is distinct from the intellect?

    (11) Whether the speculative and practical intellect are distinct powers?

    (12) Whether "synderesis" is a power of the intellectual part?

    (13) Whether the conscience is a power of the intellectual part?
 
Article: 1 

Whether the intellect is a power of the soul?

  Objection 1: It would seem that the intellect is not a power of the soul, but the essence of the soul. For the intellect seems to be the same as the mind. Now the mind is not a power of the soul, but the essence; for Augustine says (De Trin. ix, 2): "Mind and spirit are not relative things, but denominate the essence." Therefore the intellect is the essence of the soul.

  Objection 2: Further, different genera of the soul's powers are not united in some one power, but only in the essence of the soul. Now the appetitive and the intellectual are different genera of the soul's powers as the Philosopher says (De Anima ii, 3), but they are united in the mind, for Augustine (De Trin. x, 11) places the intelligence and will in the mind. Therefore the mind and intellect of man is of the very essence of the soul and not a power thereof.

  Objection 3: Further, according to Gregory, in a homily for the Ascension (xxix in Ev.), "man understands with the angels." But angels are called "minds" and "intellects." Therefore the mind and intellect of man are not a power of the soul, but the soul itself.

  Objection 4: Further, a substance is intellectual by the fact that it is immaterial. But the soul is immaterial through its essence. Therefore it seems that the soul must be intellectual through its essence.

  On the contrary, The Philosopher assigns the intellectual faculty as a power of the soul (De Anima ii, 3).

  I answer that, In accordance with what has been already shown (Question [54], Article [3]; Question [77], Article [1]) it is necessary to say that the intellect is a power of the soul, and not the very essence of the soul. For then alone the essence of that which operates is the immediate principle of operation, when operation itself is its being: for as power is to operation as its act, so is the essence to being. But in God alone His action of understanding is His very Being. Wherefore in God alone is His intellect His essence: while in other intellectual creatures, the intellect is power.

  Reply to Objection 1: Sense is sometimes taken for the power, and sometimes for the sensitive soul; for the sensitive soul takes its name from its chief power, which is sense. And in like manner the intellectual soul is sometimes called intellect, as from its chief power; and thus we read (De Anima i, 4), that the "intellect is a substance." And in this sense also Augustine says that the mind is spirit and essence (De Trin. ix, 2; xiv, 16).

  Reply to Objection 2: The appetitive and intellectual powers are different genera of powers in the soul, by reason of the different formalities of their objects. But the appetitive power agrees partly with the intellectual power and partly with the sensitive in its mode of operation either through a corporeal organ or without it: for appetite follows apprehension. And in this way Augustine puts the will in the mind; and the Philosopher, in the reason (De Anima iii, 9).

  Reply to Objection 3: In the angels there is no other power besides the intellect, and the will, which follows the intellect. And for this reason an angel is called a "mind" or an "intellect"; because his whole power consists in this. But the soul has many other powers, such as the sensitive and nutritive powers, and therefore the comparison fails.

  Reply to Objection 4: The immateriality of the created intelligent substance is not its intellect; and through its immateriality it has the power of intelligence. Wherefore it follows not that the intellect is the substance of the soul, but that it is its virtue and power.

Article: 2 

Whether the intellect is a passive power?

  Objection 1: It would seem that the intellect is not a passive power. For everything is passive by its matter, and acts by its form. But the intellectual power results from the immateriality of the intelligent substance. Therefore it seems that the intellect is not a passive power.

  Objection 2: Further, the intellectual power is incorruptible, as we have said above (Question [79], Article [6]). But "if the intellect is passive, it is corruptible" (De Anima iii, 5). Therefore the intellectual power is not passive.

  Objection 3: Further, the "agent is nobler than the patient," as Augustine (Gen. ad lit. xii, 16) and Aristotle (De Anima iii, 5) says. But all the powers of the vegetative part are active; yet they are the lowest among the powers of the soul. Much more, therefore, all the intellectual powers, which are the highest, are active.

  On the contrary, The Philosopher says (De Anima iii, 4) that "to understand is in a way to be passive."

  I answer that, To be passive may be taken in three ways. Firstly, in its most strict sense, when from a thing is taken something which belongs to it by virtue either of its nature, or of its proper inclination: as when water loses coolness by heating, and as when a man becomes ill or sad. Secondly, less strictly, a thing is said to be passive, when something, whether suitable or unsuitable, is taken away from it. And in this way not only he who is ill is said to be passive, but also he who is healed; not only he that is sad, but also he that is joyful; or whatever way he be altered or moved. Thirdly, in a wide sense a thing is said to be passive, from the very fact that what is in potentiality to something receives that to which it was in potentiality, without being deprived of anything. And accordingly, whatever passes from potentiality to act, may be said to be passive, even when it is perfected. And thus with us to understand is to be passive. This is clear from the following reason. For the intellect, as we have seen above (Question [78], Article [1]), has an operation extending to universal being. We may therefore see whether the intellect be in act or potentiality by observing first of all the nature of the relation of the intellect to universal being. For we find an intellect whose relation to universal being is that of the act of all being: and such is the Divine intellect, which is the Essence of God, in which originally and virtually, all being pre-exists as in its first cause. And therefore the Divine intellect is not in potentiality, but is pure act. But no created intellect can be an act in relation to the whole universal being; otherwise it would needs be an infinite being. Wherefore every created intellect is not the act of all things intelligible, by reason of its very existence; but is compared to these intelligible things as a potentiality to act.

   Now, potentiality has a double relation to act. There is a potentiality which is always perfected by its act: as the matter of the heavenly bodies (Question [58], Article [1]). And there is another potentiality which is not always in act, but proceeds from potentiality to act; as we observe in things that are corrupted and generated. Wherefore the angelic intellect is always in act as regards those things which it can understand, by reason of its proximity to the first intellect, which is pure act, as we have said above. But the human intellect, which is the lowest in the order of intelligence and most remote from the perfection of the Divine intellect, is in potentiality with regard to things intelligible, and is at first "like a clean tablet on which nothing is written," as the Philosopher says (De Anima iii, 4). This is made clear from the fact, that at first we are only in potentiality to understand, and afterwards we are made to understand actually. And so it is evident that with us to understand is "in a way to be passive"; taking passion in the third sense. And consequently the intellect is a passive power.

  Reply to Objection 1: This objection is verified of passion in the first and second senses, which belong to primary matter. But in the third sense passion is in anything which is reduced from potentiality to act.

  Reply to Objection 2: "Passive intellect" is the name given by some to the sensitive appetite, in which are the passions of the soul; which appetite is also called "rational by participation," because it "obeys the reason" (Ethic. i, 13). Others give the name of passive intellect to the cogitative power, which is called the "particular reason." And in each case "passive" may be taken in the two first senses; forasmuch as this so-called intellect is the act of a corporeal organ. But the intellect which is in potentiality to things intelligible, and which for this reason Aristotle calls the "possible" intellect (De Anima iii, 4) is not passive except in the third sense: for it is not an act of a corporeal organ. Hence it is incorruptible.

  Reply to Objection 3: The agent is nobler than the patient, if the action and the passion are referred to the same thing: but not always, if they refer to different things. Now the intellect is a passive power in regard to the whole universal being: while the vegetative power is active in regard to some particular thing, namely, the body as united to the soul. Wherefore nothing prevents such a passive force being nobler than such an active one.
 
Article: 3

Whether there is an active intellect?

  Objection 1: It would seem that there is no active intellect. For as the senses are to things sensible, so is our intellect to things intelligible. But because sense is in potentiality to things sensible, the sense is not said to be active, but only passive. Therefore, since our intellect is in potentiality to things intelligible, it seems that we cannot say that the intellect is active, but only that it is passive.

  Objection 2: Further, if we say that also in the senses there is something active, such as light: on the contrary, light is required for sight, inasmuch as it makes the medium to be actually luminous; for color of its own nature moves the luminous medium. But in the operation of the intellect there is no appointed medium that has to be brought into act. Therefore there is no necessity for an active intellect.

  Objection 3: Further, the likeness of the agent is received into the patient according to the nature of the patient. But the passive intellect is an immaterial power. Therefore its immaterial nature suffices for forms to be received into it immaterially. Now a form is intelligible in act from the very fact that it is immaterial. Therefore there is no need for an active intellect to make the species actually intelligible.

  On the contrary, The Philosopher says (De Anima iii, 5), "As in every nature, so in the soul is there something by which it becomes all things, and something by which it makes all things." Therefore we must admit an active intellect.

  I answer that, According to the opinion of Plato, there is no need for an active intellect in order to make things actually intelligible; but perhaps in order to provide intellectual light to the intellect, as will be explained farther on (Article [4]). For Plato supposed that the forms of natural things subsisted apart from matter, and consequently that they are intelligible: since a thing is actually intelligible from the very fact that it is immaterial. And he called such forms "species or ideas"; from a participation of which, he said that even corporeal matter was formed, in order that individuals might be naturally established in their proper genera and species: and that our intellect was formed by such participation in order to have knowledge of the genera and species of things. But since Aristotle did not allow that forms of natural things exist apart from matter, and as forms existing in matter are not actually intelligible; it follows that the natures of forms of the sensible things which we understand are not actually intelligible. Now nothing is reduced from potentiality to act except by something in act; as the senses as made actual by what is actually sensible. We must therefore assign on the part of the intellect some power to make things actually intelligible, by abstraction of the species from material conditions. And such is the necessity for an active intellect.

  Reply to Objection 1: Sensible things are found in act outside the soul; and hence there is no need for an active sense. Wherefore it is clear that in the nutritive part all the powers are active, whereas in the sensitive part all are passive: but in the intellectual part, there is something active and something passive.

  Reply to Objection 2: There are two opinions as to the effect of light. For some say that light is required for sight, in order to make colors actually visible. And according to this the active intellect is required for understanding, in like manner and for the same reason as light is required for seeing. But in the opinion of others, light is required for sight; not for the colors to become actually visible; but in order that the medium may become actually luminous, as the Commentator says on De Anima ii. And according to this, Aristotle's comparison of the active intellect to light is verified in this, that as it is required for understanding, so is light required for seeing; but not for the same reason.

  Reply to Objection 3: If the agent pre-exist, it may well happen that its likeness is received variously into various things, on account of their dispositions. But if the agent does not pre-exist, the disposition of the recipient has nothing to do with the matter. Now the intelligible in act is not something existing in nature; if we consider the nature of things sensible, which do not subsist apart from matter. And therefore in order to understand them, the immaterial nature of the passive intellect would not suffice but for the presence of the active intellect which makes things actually intelligible by way of abstraction.

Article: 4 

Whether the active intellect is something in the soul?

  Objection 1: It would seem that the active intellect is not something in the soul. For the effect of the active intellect is to give light for the purpose of understanding. But this is done by something higher than the soul: according to Jn. 1:9, "He was the true light that enlighteneth every man coming into this world." Therefore the active intellect is not something in the soul.

  Objection 2: Further, the Philosopher (De Anima iii, 5) says of the active intellect, "that it does not sometimes understand and sometimes not understand." But our soul does not always understand: sometimes it understands, sometimes it does not understand. Therefore the active intellect is not something in our soul.

  Objection 3: Further, agent and patient suffice for action. If, therefore, the passive intellect, which is a passive power, is something belonging to the soul; and also the active intellect, which is an active power: it follows that a man would always be able to understand when he wished, which is clearly false. Therefore the active intellect is not something in our soul.

  Objection 4: Further, the Philosopher (De Anima iii, 5) says that the active intellect is a "substance in actual being." But nothing can be in potentiality and in act with regard to the same thing. If, therefore, the passive intellect, which is in potentiality to all things intelligible, is something in the soul, it seems impossible for the active intellect to be also something in our soul.

  Objection 5: Further, if the active intellect is something in the soul, it must be a power. For it is neither a passion nor a habit; since habits and passions are not in the nature of agents in regard to the passivity of the soul; but rather passion is the very action of the passive power; while habit is something which results from acts. But every power flows from the essence of the soul. It would therefore follow that the active intellect flows from the essence of the soul. And thus it would not be in the soul by way of participation from some higher intellect: which is unfitting. Therefore the active intellect is not something in our soul.

  On the contrary, The Philosopher says (De Anima iii, 5), that "it is necessary for these differences," namely, the passive and active intellect, "to be in the soul."

  I answer that, The active intellect, of which the Philosopher speaks, is something in the soul. In order to make this evident, we must observe that above the intellectual soul of man we must needs suppose a superior intellect, from which the soul acquires the power of understanding. For what is such by participation, and what is mobile, and what is imperfect always requires the pre-existence of something essentially such, immovable and perfect. Now the human soul is called intellectual by reason of a participation in intellectual power; a sign of which is that it is not wholly intellectual but only in part. Moreover it reaches to the understanding of truth by arguing, with a certain amount of reasoning and movement. Again it has an imperfect understanding; both because it does not understand everything, and because, in those things which it does understand, it passes from potentiality to act. Therefore there must needs be some higher intellect, by which the soul is helped to understand.

   Wherefore some held that this intellect, substantially separate, is the active intellect, which by lighting up the phantasms as it were, makes them to be actually intelligible. But, even supposing the existence of such a separate active intellect, it would still be necessary to assign to the human soul some power participating in that superior intellect, by which power the human soul makes things actually intelligible. Just as in other perfect natural things, besides the universal active causes, each one is endowed with its proper powers derived from those universal causes: for the sun alone does not generate man; but in man is the power of begetting man: and in like manner with other perfect animals. Now among these lower things nothing is more perfect than the human soul. Wherefore we must say that in the soul is some power derived from a higher intellect, whereby it is able to light up the phantasms. And we know this by experience, since we perceive that we abstract universal forms from their particular conditions, which is to make them actually intelligible. Now no action belongs to anything except through some principle formally inherent therein; as we have said above of the passive intellect (Question [76], Article [1]). Therefore the power which is the principle of this action must be something in the soul. For this reason Aristotle (De Anima iii, 5) compared the active intellect to light, which is something received into the air: while Plato compared the separate intellect impressing the soul to the sun, as Themistius says in his commentary on De Anima iii. But the separate intellect, according to the teaching of our faith, is God Himself, Who is the soul's Creator, and only beatitude; as will be shown later on (Question [90], Article [3]; FS, Question [3], Article [7]). Wherefore the human soul derives its intellectual light from Him, according to Ps. 4:7, "The light of Thy countenance, O Lord, is signed upon us."

  Reply to Objection 1: That true light enlightens as a universal cause, from which the human soul derives a particular power, as we have explained.

  Reply to Objection 2: The Philosopher says those words not of the active intellect, but of the intellect in act: of which he had already said: "Knowledge in act is the same as the thing." Or, if we refer those words to the active intellect, then they are said because it is not owing to the active intellect that sometimes we do, and sometimes we do not understand, but to the intellect which is in potentiality.

  Reply to Objection 3: If the relation of the active intellect to the passive were that of the active object to a power, as, for instance, of the visible in act to the sight; it would follow that we could understand all things instantly, since the active intellect is that which makes all things (in act). But now the active intellect is not an object, rather is it that whereby the objects are made to be in act: for which, besides the presence of the active intellect, we require the presence of phantasms, the good disposition of the sensitive powers, and practice in this sort of operation; since through one thing understood, other things come to be understood, as from terms are made propositions, and from first principles, conclusions. From this point of view it matters not whether the active intellect is something belonging to the soul, or something separate from the soul.

  Reply to Objection 4: The intellectual soul is indeed actually immaterial, but it is in potentiality to determinate species. On the contrary, phantasms are actual images of certain species, but are immaterial in potentiality. Wherefore nothing prevents one and the same soul, inasmuch as it is actually immaterial, having one power by which it makes things actually immaterial, by abstraction from the conditions of individual matter: which power is called the "active intellect"; and another power, receptive of such species, which is called the "passive intellect" by reason of its being in potentiality to such species.

  Reply to Objection 5: Since the essence of the soul is immaterial, created by the supreme intellect, nothing prevents that power which it derives from the supreme intellect, and whereby it abstracts from matter, flowing from the essence of the soul, in the same way as its other powers.
 
Article: 5  

Whether the active intellect is one in all?

  Objection 1: It would seem that there is one active intellect in all. For what is separate from the body is not multiplied according to the number of bodies. But the active intellect is "separate," as the Philosopher says (De Anima iii, 5). Therefore it is not multiplied in the many human bodies, but is one for all men.

  Objection 2: Further, the active intellect is the cause of the universal, which is one in many. But that which is the cause of unity is still more itself one. Therefore the active intellect is the same in all.

  Objection 3: Further, all men agree in the first intellectual concepts. But to these they assent by the active intellect. Therefore all agree in one active intellect.

  On the contrary, The Philosopher says (De Anima iii, 5) that the active intellect is as a light. But light is not the same in the various things enlightened. Therefore the same active intellect is not in various men.

  I answer that, The truth about this question depends on what we have already said (Article [4]). For if the active intellect were not something belonging to the soul, but were some separate substance, there would be one active intellect for all men. And this is what they mean who hold that there is one active intellect for all. But if the active intellect is something belonging to the soul, as one of its powers, we are bound to say that there are as many active intellects as there are souls, which are multiplied according to the number of men, as we have said above (Question [76], Article [2]). For it is impossible that one same power belong to various substances.

  Reply to Objection 1: The Philosopher proves that the active intellect is separate, by the fact that the passive intellect is separate: because, as he says (De Anima iii, 5), "the agent is more noble than the patient." Now the passive intellect is said to be separate, because it is not the act of any corporeal organ. And in the same sense the active intellect is also called "separate"; but not as a separate substance.

  Reply to Objection 2: The active intellect is the cause of the universal, by abstracting it from matter. But for this purpose it need not be the same intellect in all intelligent beings; but it must be one in its relationship to all those things from which it abstracts the universal, with respect to which things the universal is one. And this befits the active intellect inasmuch as it is immaterial.

  Reply to Objection 3: All things which are of one species enjoy in common the action which accompanies the nature of the species, and consequently the power which is the principle of such action; but not so as that power be identical in all. Now to know the first intelligible principles is the action belonging to the human species. Wherefore all men enjoy in common the power which is the principle of this action: and this power is the active intellect. But there is no need for it to be identical in all. Yet it must be derived by all from one principle. And thus the possession by all men in common of the first principles proves the unity of the separate intellect, which Plato compares to the sun; but not the unity of the active intellect, which Aristotle compares to light.

Article: 6 

Whether memory is in the intellectual part of the soul?

  Objection 1: It would seem that memory is not in the intellectual part of the soul. For Augustine says (De Trin. xii, 2,3,8) that to the higher part of the soul belongs those things which are not "common to man and beast." But memory is common to man and beast, for he says (De Trin. xii, 2,3,8) that "beasts can sense corporeal things through the senses of the body, and commit them to memory." Therefore memory does not belong to the intellectual part of the soul.

  Objection 2: Further, memory is of the past. But the past is said of something with regard to a fixed time. Memory, therefore, knows a thing under a condition of a fixed time; which involves knowledge under the conditions of "here" and "now." But this is not the province of the intellect, but of the sense. Therefore memory is not in the intellectual part, but only in the sensitive.

  Objection 3: Further, in the memory are preserved the species of those things of which we are not actually thinking. But this cannot happen in the intellect, because the intellect is reduced to act by the fact that the intelligible species are received into it. Now the intellect in act implies understanding in act; and therefore the intellect actually understands all things of which it has the species. Therefore the memory is not in the intellectual part.

  On the contrary, Augustine says (De Trin. x, 11) that "memory, understanding, and will are one mind."

  I answer that, Since it is of the nature of the memory to preserve the species of those things which are not actually apprehended, we must first of all consider whether the intelligible species can thus be preserved in the intellect: because Avicenna held that this was impossible. For he admitted that this could happen in the sensitive part, as to some powers, inasmuch as they are acts of corporeal organs, in which certain species may be preserved apart from actual apprehension. But in the intellect, which has no corporeal organ, nothing but what is intelligible exists. Wherefore every thing of which the likeness exists in the intellect must be actually understood. Thus, therefore, according to him, as soon as we cease to understand something actually, the species of that thing ceases to be in our intellect, and if we wish to understand that thing anew, we must turn to the active intellect, which he held to be a separate substance, in order that the intelligible species may thence flow again into our passive intellect. And from the practice and habit of turning to the active intellect there is formed, according to him, a certain aptitude in the passive intellect for turning to the active intellect; which aptitude he calls the habit of knowledge. According, therefore, to this supposition, nothing is preserved in the intellectual part that is not actually understood: wherefore it would not be possible to admit memory in the intellectual part.

   But this opinion is clearly opposed to the teaching of Aristotle. For he says (De Anima iii, 4) that, when the passive intellect "is identified with each thing as knowing it, it is said to be in act," and that "this happens when it can operate of itself. And, even then, it is in potentiality, but not in the same way as before learning and discovering." Now, the passive intellect is said to be each thing, inasmuch as it receives the intelligible species of each thing. To the fact, therefore, that it receives the species of intelligible things it owes its being able to operate when it wills, but not so that it be always operating: for even then is it in potentiality in a certain sense, though otherwise than before the act of understanding---namely, in the sense that whoever has habitual knowledge is in potentiality to actual consideration.

   The foregoing opinion is also opposed to reason. For what is received into something is received according to the conditions of the recipient. But the intellect is of a more stable nature, and is more immovable than corporeal nature. If, therefore, corporeal matter holds the forms which it receives, not only while it actually does something through them, but also after ceasing to act through them, much more cogent reason is there for the intellect to receive the species unchangeably and lastingly, whether it receive them from things sensible, or derive them from some superior intellect. Thus, therefore, if we take memory only for the power of retaining species, we must say that it is in the intellectual part. But if in the notion of memory we include its object as something past, then the memory is not in the intellectual, but only in the sensitive part, which apprehends individual things. For past, as past, since it signifies being under a condition of fixed time, is something individual.

  Reply to Objection 1: Memory, if considered as retentive of species, is not common to us and other animals. For species are not retained in the sensitive part of the soul only, but rather in the body and soul united: since the memorative power is the act of some organ. But the intellect in itself is retentive of species, without the association of any corporeal organ. Wherefore the Philosopher says (De Anima iii, 4) that "the soul is the seat of the species, not the whole soul, but the intellect."

  Reply to Objection 2: The condition of past may be referred to two things---namely, to the object which is known, and to the act of knowledge. These two are found together in the sensitive part, which apprehends something from the fact of its being immuted by a present sensible: wherefore at the same time an animal remembers to have sensed before in the past, and to have sensed some past sensible thing. But as concerns the intellectual part, the past is accidental, and is not in itself a part of the object of the intellect. For the intellect understands man, as man: and to man, as man, it is accidental that he exist in the present, past, or future. But on the part of the act, the condition of past, even as such, may be understood to be in the intellect, as well as in the senses. Because our soul's act of understanding is an individual act, existing in this or that time, inasmuch as a man is said to understand now, or yesterday, or tomorrow. And this is not incompatible with the intellectual nature: for such an act of understanding, though something individual, is yet an immaterial act, as we have said above of the intellect (Question [76], Article [1]); and therefore, as the intellect understands itself, though it be itself an individual intellect, so also it understands its act of understanding, which is an individual act, in the past, present, or future. In this way, then, the notion of memory, in as far as it regards past events, is preserved in the intellect, forasmuch as it understands that it previously understood: but not in the sense that it understands the past as something "here" and "now."

  Reply to Objection 3: The intelligible species is sometimes in the intellect only in potentiality, and then the intellect is said to be in potentiality. Sometimes the intelligible species is in the intellect as regards the ultimate completion of the act, and then it understands in act. And sometimes the intelligible species is in a middle state, between potentiality and act: and then we have habitual knowledge. In this way the intellect retains the species, even when it does not understand in act.
 
Article: 7

Whether the intellectual memory is a power distinct from the intellect?

  Objection 1: It would seem that the intellectual memory is distinct from the intellect. For Augustine (De Trin. x, 11) assigns to the soul memory, understanding, and will. But it is clear that the memory is a distinct power from the will. Therefore it is also distinct from the intellect.

  Objection 2: Further, the reason of distinction among the powers in the sensitive part is the same as in the intellectual part. But memory in the sensitive part is distinct from sense, as we have said (Question [78], Article [4]). Therefore memory in the intellectual part is distinct from the intellect.

  Objection 3: Further, according to Augustine (De Trin. x, 11; xi, 7), memory, understanding, and will are equal to one another, and one flows from the other. But this could not be if memory and intellect were the same power. Therefore they are not the same power.

  On the contrary, From its nature the memory is the treasury or storehouse of species. But the Philosopher (De Anima iii) attributes this to the intellect, as we have said (Article [6], ad 1). Therefore the memory is not another power from the intellect.

  I answer that, As has been said above (Question [77], Article [3]), the powers of the soul are distinguished by the different formal aspects of their objects: since each power is defined in reference to that thing to which it is directed and which is its object. It has also been said above (Question [59], Article [4]) that if any power by its nature be directed to an object according to the common ratio of the object, that power will not be differentiated according to the individual differences of that object: just as the power of sight, which regards its object under the common ratio of color, is not differentiated by differences of black and white. Now, the intellect regards its object under the common ratio of being: since the passive intellect is that "in which all are in potentiality." Wherefore the passive intellect is not differentiated by any difference of being. Nevertheless there is a distinction between the power of the active intellect and of the passive intellect: because as regards the same object, the active power which makes the object to be in act must be distinct from the passive power, which is moved by the object existing in act. Thus the active power is compared to its object as a being in act is to a being in potentiality; whereas the passive power, on the contrary, is compared to its object as being in potentiality is to a being in act. Therefore there can be no other difference of powers in the intellect, but that of passive and active. Wherefore it is clear that memory is not a distinct power from the intellect: for it belongs to the nature of a passive power to retain as well as to receive.

  Reply to Objection 1: Although it is said (3 Sent. D, 1) that memory, intellect, and will are three powers, this is not in accordance with the meaning of Augustine, who says expressly (De Trin. xiv) that "if we take memory, intelligence, and will as always present in the soul, whether we actually attend to them or not, they seem to pertain to the memory only. And by intelligence I mean that by which we understand when actually thinking; and by will I mean that love or affection which unites the child and its parent." Wherefore it is clear that Augustine does not take the above three for three powers; but by memory he understands the soul's habit of retention; by intelligence, the act of the intellect; and by will, the act of the will.

  Reply to Objection 2: Past and present may differentiate the sensitive powers, but not the intellectual powers, for the reason give above.

  Reply to Objection 3: Intelligence arises from memory, as act from habit; and in this way it is equal to it, but not as a power to a power.
 
Article: 8 

Whether the reason is distinct from the intellect?

  Objection 1: It would seem that the reason is a distinct power from the intellect. For it is stated in De Spiritu et Anima that "when we wish to rise from lower things to higher, first the sense comes to our aid, then imagination, then reason, then the intellect." Therefore the reason is distinct from the intellect, as imagination is from sense.

  Objection 2: Further, Boethius says (De Consol. iv, 6), that intellect is compared to reason, as eternity to time. But it does not belong to the same power to be in eternity and to be in time. Therefore reason and intellect are not the same power.

  Objection 3: Further, man has intellect in common with the angels, and sense in common with the brutes. But reason, which is proper to man, whence he is called a rational animal, is a power distinct from sense. Therefore is it equally true to say that it is distinct from the intellect, which properly belongs to the angel: whence they are called intellectual.

  On the contrary, Augustine says (Gen. ad lit. iii, 20) that "that in which man excels irrational animals is reason, or mind, or intelligence or whatever appropriate name we like to give it." Therefore, reason, intellect and mind are one power.

  I answer that, Reason and intellect in man cannot be distinct powers. We shall understand this clearly if we consider their respective actions. For to understand is simply to apprehend intelligible truth: and to reason is to advance from one thing understood to another, so as to know an intelligible truth. And therefore angels, who according to their nature, possess perfect knowledge of intelligible truth, have no need to advance from one thing to another; but apprehend the truth simply and without mental discussion, as Dionysius says (Div. Nom. vii). But man arrives at the knowledge of intelligible truth by advancing from one thing to another; and therefore he is called rational. Reasoning, therefore, is compared to understanding, as movement is to rest, or acquisition to possession; of which one belongs to the perfect, the other to the imperfect. And since movement always proceeds from something immovable, and ends in something at rest; hence it is that human reasoning, by way of inquiry and discovery, advances from certain things simply understood---namely, the first principles; and, again, by way of judgment returns by analysis to first principles, in the light of which it examines what it has found. Now it is clear that rest and movement are not to be referred to different powers, but to one and the same, even in natural things: since by the same nature a thing is moved towards a certain place. Much more, therefore, by the same power do we understand and reason: and so it is clear that in man reason and intellect are the same power.

  Reply to Objection 1: That enumeration is made according to the order of actions, not according to the distinction of powers. Moreover, that book is not of great authority.

  Reply to Objection 2: The answer is clear from what we have said. For eternity is compared to time as immovable to movable. And thus Boethius compared the intellect to eternity, and reason to time.

  Reply to Objection 3: Other animals are so much lower than man that they cannot attain to the knowledge of truth, which reason seeks. But man attains, although imperfectly, to the knowledge of intelligible truth, which angels know. Therefore in the angels the power of knowledge is not of a different genus fro that which is in the human reason, but is compared to it as the perfect to the imperfect.
 
Article: 9 

Whether the higher and lower reason are distinct powers?

  Objection 1: It would seem that the higher and lower reason are distinct powers. For Augustine says (De Trin. xii, 4,7), that the image of the Trinity is in the higher part of the reason, and not in the lower. But the parts of the soul are its powers. Therefore the higher and lower reason are two powers.

  Objection 2: Further, nothing flows from itself. Now, the lower reason flows from the higher, and is ruled and directed by it. Therefore the higher reason is another power from the lower.

  Objection 3: Further, the Philosopher says (Ethic. vi, 1) that "the scientific part" of the soul, by which the soul knows necessary things, is another principle, and another part from the "opinionative" and "reasoning" part by which it knows contingent things. And he proves this from the principle that for those things which are "generically different, generically different parts of the soul are ordained." Now contingent and necessary are generically different, as corruptible and incorruptible. Since, therefore, necessary is the same as eternal, and temporal the same as contingent, it seems that what the Philosopher calls the "scientific" part must be the same as the higher reason, which, according to Augustine (De Trin. xii, 7) "is intent on the consideration and consultation of things eternal"; and that what the Philosopher calls the "reasoning" or "opinionative" part is the same as the lower reason, which, according to Augustine, "is intent on the disposal of temporal things." Therefore the higher reason is another power than the lower.

  Objection 4: Further, Damascene says (De Fide Orth. ii) that "opinion rises from the imagination: then the mind by judging of the truth or error of the opinion discovers the truth: whence" men's (mind) "is derived from" metiendo [measuring]. "And therefore the intellect regards those things which are already subject to judgment and true decision." Therefore the opinionative power, which is the lower reason, is distinct from the mind and the intellect, by which we may understand the higher reason.

  On the contrary, Augustine says (De Trin. xii, 4) that "the higher and lower reason are only distinct by their functions." Therefore they are not two powers.

  I answer that, The higher and lower reason, as they are understood by Augustine, can in no way be two powers of the soul. For he says that "the higher reason is that which is intent on the contemplation and consultation of things eternal": forasmuch as in contemplation it sees them in themselves, and in consultation it takes its rules of action from them. But he calls the lower reason that which "is intent on the disposal of temporal things." Now these two---namely, eternal and temporal ---are related to our knowledge in this way, that one of them is the means of knowing the other. For by way of discovery, we come through knowledge of temporal things to that of things eternal, according to the words of the Apostle (Rm. 1:20), "The invisible things of God are clearly seen, being understood by the things that are made": while by way of judgment, from eternal things already known, we judge of temporal things, and according to laws of things eternal we dispose of temporal things.

   But it may happen that the medium and what is attained thereby belong to different habits: as the first indemonstrable principles belong to the habit of the intellect; whereas the conclusions which we draw from them belong to the habit of science. And so it happens that from the principles of geometry we draw a conclusion in another science---for example, perspective. But the power of the reason is such that both medium and term belong to it. For the act of the reason is, as it were, a movement from one thing to another. But the same movable thing passes through the medium and reaches the end. Wherefore the higher and lower reasons are one and the same power. But according to Augustine they are distinguished by the functions of their actions, and according to their various habits: for wisdom is attributed to the higher reason, science to the lower.

  Reply to Objection 1: We speak of parts, in whatever way a thing is divided. And so far as reason is divided according to its various acts, the higher and lower reason are called parts; but not because they are different powers.

  Reply to Objection 2: The lower reason is said to flow from the higher, or to be ruled by it, as far as the principles made use of by the lower reason are drawn from and directed by the principles of the higher reason.

  Reply to Objection 3: The "scientific" part, of which the Philosopher speaks, is not the same as the higher reason: for necessary truths are found even among temporal things, of which natural science and mathematics treat. And the "opinionative" and "ratiocinative" part is more limited than the lower reason; for it regards only things contingent. Neither must we say, without any qualification, that a power, by which the intellect knows necessary things, is distinct from a power by which it knows contingent things: because it knows both under the same objective aspect---namely, under the aspect of being and truth. Wherefore it perfectly knows necessary things which have perfect being in truth; since it penetrates to their very essence, from which it demonstrates their proper accidents. On the other hand, it knows contingent things, but imperfectly; forasmuch as they have but imperfect being and truth. Now perfect and imperfect in the action do not vary the power, but they vary the actions as to the mode of acting, and consequently the principles of the actions and the habits themselves. And therefore the Philosopher postulates two lesser parts of the soul---namely, the "scientific" and the "ratiocinative," not because they are two powers, but because they are distinct according to a different aptitude for receiving various habits, concerning the variety of which he inquires. For contingent and necessary, though differing according to their proper genera, nevertheless agree in the common aspect of being, which the intellect considers, and to which they are variously compared as perfect and imperfect.

  Reply to Objection 4: That distinction given by Damascene is according to the variety of acts, not according to the variety of powers. For "opinion" signifies an act of the intellect which leans to one side of a contradiction, whilst in fear of the other. While to "judge" or "measure" [mensurare] is an act of the intellect, applying certain principles to examine propositions. From this is taken the word "mens" [mind]. Lastly, to "understand" is to adhere to the formed judgment with approval.

Article: 10 

Whether intelligence is a power distinct from intellect?

  Objection 1: It would seem that the intelligence is another power than the intellect. For we read in De Spiritu et Anima that "when we wish to rise from lower to higher things, first the sense comes to our aid, then imagination, then reason, then intellect, and afterwards intelligence." But imagination and sense are distinct powers. Therefore also intellect and intelligence are distinct.

  Objection 2: Further, Boethius says (De Consol. v, 4) that "sense considers man in one way, imagination in another, reason in another, intelligence in another." But intellect is the same power as reason. Therefore, seemingly, intelligence is a distinct power from intellect, as reason is a distinct power from imagination or sense.

  Objection 3: Further, "actions came before powers," as the Philosopher says (De Anima ii, 4). But intelligence is an act separate from others attributed to the intellect. For Damascene says (De Fide Orth. ii) that "the first movement is called intelligence; but that intelligence which is about a certain thing is called intention; that which remains and conforms the soul to that which is understood is called invention, and invention when it remains in the same man, examining and judging of itself, is called phronesis [that is, wisdom], and phronesis if dilated makes thought, that is, orderly internal speech; from which, they say, comes speech expressed by the tongue." Therefore it seems that intelligence is some special power.

  On the contrary, The Philosopher says (De Anima iii, 6) that "intelligence is of indivisible things in which there is nothing false." But the knowledge of these things belongs to the intellect. Therefore intelligence is not another power than the intellect.

  I answer that, This word "intelligence" properly signifies the intellect's very act, which is to understand. However, in some works translated from the Arabic, the separate substances which we call angels are called "intelligences," and perhaps for this reason, that such substances are always actually understanding. But in works translated from the Greek, they are called "intellects" or "minds." Thus intelligence is not distinct from intellect, as power is from power; but as act is from power. And such a division is recognized even by the philosophers. For sometimes they assign four intellects---namely, the "active" and "passive" intellects, the intellect "in habit," and the "actual" intellect. Of which four the active and passive intellects are different powers; just as in all things the active power is distinct from the passive. But three of these are distinct, as three states of the passive intellect, which is sometimes in potentiality only, and thus it is called passive; sometimes it is in the first act, which is knowledge, and thus it is called intellect in habit; and sometimes it is in the second act, which is to consider, and thus it is called intellect in act, or actual intellect.

  Reply to Objection 1: If this authority is accepted, intelligence there means the act of the intellect. And thus it is divided against intellect as act against power.

  Reply to Objection 2: Boethius takes intelligence as meaning that act of the intellect which transcends the act of the reason. Wherefore he also says that reason alone belongs to the human race, as intelligence alone belongs to God, for it belongs to God to understand all things without any investigation.

  Reply to Objection 3: All those acts which Damascene enumerates belong to one power---namely, the intellectual power. For this power first of all only apprehends something; and this act is called "intelligence." Secondly, it directs what it apprehends to the knowledge of something else, or to some operation; and this is called "intention." And when it goes on in search of what it "intends," it is called "invention." When, by reference to something known for certain, it examines what it has found, it is said to know or to be wise, which belongs to "phronesis" or "wisdom"; for "it belongs to the wise man to judge," as the Philosopher says (Metaph. i, 2). And when once it has obtained something for certain, as being fully examined, it thinks about the means of making it known to others; and this is the ordering of "interior speech," from which proceeds "external speech." For every difference of acts does not make the powers vary, but only what cannot be reduced to the one same principle, as we have said above (Question [78], Article [4]).
 
Article: 11 

Whether the speculative and practical intellects are distinct powers?

  Objection 1: It would seem that the speculative and practical intellects are distinct powers. For the apprehensive and motive are different kinds of powers, as is clear from De Anima ii, 3. But the speculative intellect is merely an apprehensive power; while the practical intellect is a motive power. Therefore they are distinct powers.

  Objection 2: Further, the different nature of the object differentiates the power. But the object of the speculative intellect is "truth," and of the practical is "good"; which differ in nature. Therefore the speculative and practical intellect are distinct powers.

  Objection 3: Further, in the intellectual part, the practical intellect is compared to the speculative, as the estimative is to the imaginative power in the sensitive part. But the estimative differs from the imaginative, as power form power, as we have said above (Question [78], Article [4]). Therefore also the speculative intellect differs from the practical.

  On the contrary, The speculative intellect by extension becomes practical (De Anima iii, 10). But one power is not changed into another. Therefore the speculative and practical intellects are not distinct powers.

  I answer that, The speculative and practical intellects are not distinct powers. The reason of which is that, as we have said above (Question [77], Article [3]), what is accidental to the nature of the object of a power, does not differentiate that power; for it is accidental to a thing colored to be man, or to be great or small; hence all such things are apprehended by the same power of sight. Now, to a thing apprehended by the intellect, it is accidental whether it be directed to operation or not, and according to this the speculative and practical intellects differ. For it is the speculative intellect which directs what it apprehends, not to operation, but to the consideration of truth; while the practical intellect is that which directs what it apprehends to operation. And this is what the Philosopher says (De Anima iii, 10); that "the speculative differs from the practical in its end." Whence each is named from its end: the one speculative, the other practical---i.e. operative.

  Reply to Objection 1: The practical intellect is a motive power, not as executing movement, but as directing towards it; and this belongs to it according to its mode of apprehension.

  Reply to Objection 2: Truth and good include one another; for truth is something good, otherwise it would not be desirable; and good is something true, otherwise it would not be intelligible. Therefore as the object of the appetite may be something true, as having the aspect of good, for example, when some one desires to know the truth; so the object of the practical intellect is good directed to the operation, and under the aspect of truth. For the practical intellect knows truth, just as the speculative, but it directs the known truth to operation.

  Reply to Objection 3: Many differences differentiate the sensitive powers, which do not differentiate the intellectual powers, as we have said above (Article [7], ad 2; Question [77], Article [3], ad 4).
 
Article: 12 

Whether synderesis is a special power of the soul distinct from the others?

  Objection 1: It would seem that "synderesis" is a special power, distinct from the others. For those things which fall under one division, seem to be of the same genus. But in the gloss of Jerome on Ezech. 1:6, "synderesis" is divided against the irascible, the concupiscible, and the rational, which are powers. Therefore "synderesis" is a power.

  Objection 2: Further, opposite things are of the same genus. But "synderesis" and sensuality seem to be opposed to one another because "synderesis" always incites to good; while sensuality always incites to evil: whence it is signified by the serpent, as is clear from Augustine (De Trin. xii, 12,13). It seems, therefore, that 'synderesis' is a power just as sensuality is.

  Objection 3: Further, Augustine says (De Lib. Arb. ii, 10) that in the natural power of judgment there are certain "rules and seeds of virtue, both true and unchangeable." And this is what we call synderesis. Since, therefore, the unchangeable rules which guide our judgment belong to the reason as to its higher part, as Augustine says (De Trin. xii, 2), it seems that "synderesis" is the same as reason: and thus it is a power.

  On the contrary, According to the Philosopher (Metaph. viii, 2), "rational powers regard opposite things." But "synderesis" does not regard opposites, but inclines to good only. Therefore "synderesis" is not a power. For if it were a power it would be a rational power, since it is not found in brute animals.

  I answer that, "Synderesis" is not a power but a habit; though some held that it is a power higher than reason; while others [*Cf. Alexander of Hales, Sum. Theol. II, Question [73]] said that it is reason itself, not as reason, but as a nature. In order to make this clear we must observe that, as we have said above (Article [8]), man's act of reasoning, since it is a kind of movement, proceeds from the understanding of certain things---namely, those which are naturally known without any investigation on the part of reason, as from an immovable principle---and ends also at the understanding, inasmuch as by means of those principles naturally known, we judge of those things which we have discovered by reasoning. Now it is clear that, as the speculative reason argues about speculative things, so that practical reason argues about practical things. Therefore we must have, bestowed on us by nature, not only speculative principles, but also practical principles. Now the first speculative principles bestowed on us by nature do not belong to a special power, but to a special habit, which is called "the understanding of principles," as the Philosopher explains (Ethic. vi, 6). Wherefore the first practical principles, bestowed on us by nature, do not belong to a special power, but to a special natural habit, which we call "synderesis." Whence "synderesis" is said to incite to good, and to murmur at evil, inasmuch as through first principles we proceed to discover, and judge of what we have discovered. It is therefore clear that "synderesis" is not a power, but a natural habit.

  Reply to Objection 1: The division given by Jerome is taken from the variety of acts, and not from the variety of powers; and various acts can belong to one power.

  Reply to Objection 2: In like manner, the opposition of sensuality to "syneresis" is an opposition of acts, and not of the different species of one genus.

  Reply to Objection 3: Those unchangeable notions are the first practical principles, concerning which no one errs; and they are attributed to reason as to a power, and to "synderesis" as to a habit. Wherefore we judge naturally both by our reason and by "synderesis."

Article: 13 

Whether conscience be a power?

  Objection 1: It would seem that conscience is a power; for Origen says [*Commentary on Rm. 2:15] that "conscience is a correcting and guiding spirit accompanying the soul, by which it is led away from evil and made to cling to good." But in the soul, spirit designates a power---either the mind itself, according to the text (Eph. 4:13), "Be ye renewed in the spirit of your mind"---or the imagination, whence imaginary vision is called spiritual, as Augustine says (Gen. ad lit. xii, 7,24). Therefore conscience is a power.

  Objection 2: Further, nothing is a subject of sin, except a power of the soul. But conscience is a subject of sin; for it is said of some that "their mind and conscience are defiled" (Titus 1:15). Therefore it seems that conscience is a power.

  Objection 3: Further, conscience must of necessity be either an act, a habit, or a power. But it is not an act; for thus it would not always exist in man. Nor is it a habit; for conscience is not one thing but many, since we are directed in our actions by many habits of knowledge. Therefore conscience is a power.

  On the contrary, Conscience can be laid aside. But a power cannot be laid aside. Therefore conscience is not a power.

  I answer that, Properly speaking, conscience is not a power, but an act. This is evident both from the very name and from those things which in the common way of speaking are attributed to conscience. For conscience, according to the very nature of the word, implies the relation of knowledge to something: for conscience may be resolved into "cum alio scientia," i.e. knowledge applied to an individual case. But the application of knowledge to something is done by some act. Wherefore from this explanation of the name it is clear that conscience is an act.

   The same is manifest from those things which are attributed to conscience. For conscience is said to witness, to bind, or incite, and also to accuse, torment, or rebuke. And all these follow the application of knowledge or science to what we do: which application is made in three ways. One way in so far as we recognize that we have done or not done something; "Thy conscience knoweth that thou hast often spoken evil of others" (Eccles. 7:23), and according to this, conscience is said to witness. In another way, so far as through the conscience we judge that something should be done or not done; and in this sense, conscience is said to incite or to bind. In the third way, so far as by conscience we judge that something done is well done or ill done, and in this sense conscience is said to excuse, accuse, or torment. Now, it is clear that all these things follow the actual application of knowledge to what we do. Wherefore, properly speaking, conscience denominates an act. But since habit is a principle of act, sometimes the name conscience is given to the first natural habit---namely, 'synderesis': thus Jerome calls 'synderesis' conscience (Gloss. Ezech. 1:6); Basil [*Hom. in princ. Proverb.], the "natural power of judgment," and Damascene [*De Fide Orth. iv. 22] says that it is the "law of our intellect." For it is customary for causes and effects to be called after one another.

  Reply to Objection 1: Conscience is called a spirit, so far as spirit is the same as mind; because conscience is a certain pronouncement of the mind.

  Reply to Objection 2: The conscience is said to be defiled, not as a subject, but as the thing known is in knowledge; so far as someone knows he is defiled.

  Reply to Objection 3: Although an act does not always remain in itself, yet it always remains in its cause, which is power and habit. Now all the habits by which conscience is formed, although many, nevertheless have their efficacy from one first habit, the habit of first principles, which is called "synderesis." And for this special reason, this habit is sometimes called conscience, as we have said above.

Question: 80  OF THE APPETITIVE POWERS IN GENERAL (TWO ARTICLES)

   Next we consider the appetitive powers, concerning which there are four heads of consideration: first, the appetitive powers in general; second, sensuality; third, the will; fourth, the free-will. Under the first there are two points of inquiry:

    (1) Whether the appetite should be considered a special power of the soul?

    (2) Whether the appetite should be divided into intellectual and sensitive as distinct powers?

Article: 1 

Whether the appetite is a special power of the soul?

  Objection 1: It would seem that the appetite is not a special power of the soul. For no power of the soul is to be assigned for those things which are common to animate and to inanimate things. But appetite is common to animate and inanimate things: since "all desire good," as the Philosopher says (Ethic. i, 1). Therefore the appetite is not a special power of the soul.

  Objection 2: Further, powers are differentiated by their objects. But what we desire is the same as what we know. Therefore the appetitive power is not distinct from the apprehensive power.

  Objection 3: Further, the common is not divided from the proper. But each power of the soul desires some particular desirable thing---namely its own suitable object. Therefore, with regard to this object which is the desirable in general, we should not assign some particular power distinct from the others, called the appetitive power.

  On the contrary, The Philosopher distinguishes (De Anima ii, 3) the appetitive from the other powers. Damascene also (De Fide Orth. ii, 22) distinguishes the appetitive from the cognitive powers.

  I answer that, It is necessary to assign an appetitive power to the soul. To make this evident, we must observe that some inclination follows every form: for example, fire, by its form, is inclined to rise, and to generate its like. Now, the form is found to have a more perfect existence in those things which participate knowledge than in those which lack knowledge. For in those which lack knowledge, the form is found to determine each thing only to its own being---that is, to its nature. Therefore this natural form is followed by a natural inclination, which is called the natural appetite. But in those things which have knowledge, each one is determined to its own natural being by its natural form, in such a manner that it is nevertheless receptive of the species of other things: for example, sense receives the species of all things sensible, and the intellect, of all things intelligible, so that the soul of man is, in a way, all things by sense and intellect: and thereby, those things that have knowledge, in a way, approach to a likeness to God, "in Whom all things pre-exist," as Dionysius says (Div. Nom. v).

   Therefore, as forms exist in those things that have knowledge in a higher manner and above the manner of natural forms; so must there be in them an inclination surpassing the natural inclination, which is called the natural appetite. And this superior inclination belongs to the appetitive power of the soul, through which the animal is able to desire what it apprehends, and not only that to which it is inclined by its natural form. And so it is necessary to assign an appetitive power to the soul.

  Reply to Objection 1: Appetite is found in things which have knowledge, above the common manner in which it is found in all things, as we have said above. Therefore it is necessary to assign to the soul a particular power.

  Reply to Objection 2: What is apprehended and what is desired are the same in reality, but differ in aspect: for a thing is apprehended as something sensible or intelligible, whereas it is desired as suitable or good. Now, it is diversity of aspect in the objects, and not material diversity, which demands a diversity of powers.

  Reply to Objection 3: Each power of the soul is a form or nature, and has a natural inclination to something. Wherefore each power desires by the natural appetite that object which is suitable to itself. Above which natural appetite is the animal appetite, which follows the apprehension, and by which something is desired not as suitable to this or that power, such as sight for seeing, or sound for hearing; but simply as suitable to the animal.
 
Article: 2 

Whether the sensitive and intellectual appetites are distinct powers?

  Objection 1: It would seem that the sensitive and intellectual appetites are not distinct powers. For powers are not differentiated by accidental differences, as we have seen above (Question [77], Article [3]). But it is accidental to the appetible object whether it be apprehended by the sense or by the intellect. Therefore the sensitive and intellectual appetites are not distinct powers.

  Objection 2: Further, intellectual knowledge is of universals; and so it is distinct from sensitive knowledge, which is of individual things. But there is no place for this distinction in the appetitive part: for since the appetite is a movement of the soul to individual things, seemingly every act of the appetite regards an individual thing. Therefore the intellectual appetite is not distinguished from the sensitive.

  Objection 3: Further, as under the apprehensive power, the appetitive is subordinate as a lower power, so also is the motive power. But the motive power which in man follows the intellect is not distinct from the motive power which in animals follows sense. Therefore, for a like reason, neither is there distinction in the appetitive part.

  On the contrary, The Philosopher (De Anima iii, 9) distinguishes a double appetite, and says (De Anima iii, 11) that the higher appetite moves the lower.

  I answer that, We must needs say that the intellectual appetite is a distinct power from the sensitive appetite. For the appetitive power is a passive power, which is naturally moved by the thing apprehended: wherefore the apprehended appetible is a mover which is not moved, while the appetite is a mover moved, as the Philosopher says in De Anima iii, 10 and Metaph. xii (Did. xi, 7). Now things passive and movable are differentiated according to the distinction of the corresponding active and motive principles; because the motive must be proportionate to the movable, and the active to the passive: indeed, the passive power itself has its very nature from its relation to its active principle. Therefore, since what is apprehended by the intellect and what is apprehended by sense are generically different; consequently, the intellectual appetite is distinct from the sensitive.

  Reply to Objection 1: It is not accidental to the thing desired to be apprehended by the sense or the intellect; on the contrary, this belongs to it by its nature; for the appetible does not move the appetite except as it is apprehended. Wherefore differences in the thing apprehended are of themselves differences of the appetible. And so the appetitive powers are distinct according to the distinction of the things apprehended, as their proper objects.

  Reply to Objection 2: The intellectual appetite, though it tends to individual things which exist outside the soul, yet tends to them as standing under the universal; as when it desires something because it is good. Wherefore the Philosopher says (Rhetoric. ii, 4) that hatred can regard a universal, as when "we hate every kind of thief." In the same way by the intellectual appetite we may desire the immaterial good, which is not apprehended by sense, such as knowledge, virtue, and suchlike.