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 o