Summa contra Gentiles2.80 Chapter LXXX and LXXXI. Arguments to prove that the soul is corrupted when the body is corrupted

Certain arguments would seem to show that human souls cannot possibly remain after the body.

For if human souls are multiplied according to the multiplication of bodies, as we have proved above, it follows that when the bodies are destroyed, the souls cannot remain in their multitude. Wherefore one of two alternatives must follow: either that the human soul altogether ceases to exist; or that only one remains. And this would seem to concur with the opinion of those who state that only that which is one in all men is incorruptible, whether this be the active intellect alone, as Alexander says, or the possible besides the active intellect, according to Averroes.' Moreover. The formal ratio is the cause of specific difference. Now, if many souls remain after the corruption of bodies, they must differ from each other: because, as there is identity where there is oneness of substance, so is there difference where there are many in substance. But in souls that survive bodies there can be no difference other than formal, since they are not composed of matter and form, as we have proved above' of every intellectual substance. Hence it follows that they differ specifically. And yet souls are not changed to another species by the corruption of the body, since whatever is changed from species to species is corrupted. It follows therefore that even before they were separated from their bodies, they were different in species. Now composites derive their species from their Form. Consequently individual men will differ specifically. Which is absurd. Therefore it is seemingly impossible hat many souls should survive their bodies.

Again. According to those who hold the eternity of the world it would seem altogether impossible to maintain that human souls remain in their multitude after the death of he body. For if the world exists from eternity, movement is from eternity: and consequently generation also is eternal. But if generation be eternal, an infinite number of men have died before us. Consequently, if the souls of the dead remain in their multitude after death, we must say that there is actually an infinite number of souls of men already dead. But this is impossible: since the actually infinite cannot exist in nature. Therefore it follows, if the world is eternal, that souls do not remain many after death.

Again. That which accrues to a thing and departs from it without the latter being corrupted, accrues to it accidentally, for this is the definition of an accident. Hence if the soul be not corrupted when parted from the body, it would follow that the soul is united to the body accidentally. Consequently man is an accidental being, composed of soul and body. And it will follow moreover that there is no human species, since one species does not result from things united accidentally; for white man is not a species.

Moreover. There cannot possibly be a substance that has no operation. Now all operation of the soul ends with the body; which is proved by induction. For the nutritive powers of the soul operate through the bodily qualities, and through a bodily instrument, and act on the body which is perfected by the soul, is nourished and increased, and from which is severed the seed for the purpose of generation. Again, all the operations of the powers belonging to the sensitive soul are accomplished through bodily organs: some of them being accomplished with a certain bodily transmutation, for instance those which are called passions of the soul, such as love, joy, and the like. Moreover, though understanding is not an operation fulfilled through a bodily organ, yet its objects are the phantasms which stand in relation to it, as colours to the sight:' wherefore, as the sight cannot see without colours, so the intellective soul cannot understand without phantasms.

Further, the soul, in order to understand, needs the powers which prepare the phantasms so as to make them actually intelligible, namely the cogitative power and the memory, which clearly cannot remain after the body, since they are acts of certain organs of the body, and operate through those organs. Hence Aristotle says that the soul does not understand ivithout phantasms, and that it understands nothing ivithout the passive intellect,' which he calls the cogitative power, and which is corruptible. For this reason he says (i De AnimaY that man's act of understanding is corrupted when something within him is corrupted, namely the phantasm or the passive intellect. And it is stated in 3 De Anima that after death we do not remember what we knew in life. It is accordingly evident that no operation of the soul can remain after death. Therefore neither does its substance remain, since no substance can be without operation.

Now, since these arguments lead to a false conclusion, as was shown above, we must endeavour to answer them. And, in the first place, it must be observed that whatever things have to be adapted and proportionate to one another, are together multiplied or unified, each by its own cause. Wherefore if the being of one depends on the other, its unity or multiplicity depends also thereon; otherwise it depends on some other extrinsic cause. Now form and matter need always to be mutually proportionate and naturally adapted, so to speak, because the proper act is produced in its proper matter. Consequently matter and form must always agree in point of multitude and unity. Hence if the being of the form depend on matter, its multiplication, as also its unity, depends on matter. But if not, the form must needs be multiplied according to the multiplication of the matter, that is together with matter, and in proportion thereto: yet not so that the unity or multiplicity of the very form depend on matter. Now it has been shown that the human soul is a form independent of matter as to its being. Wherefore it follows that souls are indeed multiplied according as bodies are multiplied, and yet the multiplication of bodies is not the cause of the multiplication of souls. Therefore it does not follow that the plurality of souls ceases with the destruction of bodies, as the first argument concluded.

From this the reply also to the second argument is clear. For it is not every difference of forms that causes a difference of species, but only that which is in respect of formal principles, or of a different kind of form; since it is clear that the form is essentially distinct in this and that fire, and yet neither fire nor form is specifically different. Accordingly multitude of souls separated from their bodies results from the substantial distinction of forms, since one soul is substantially distinct from another, and yet this distinction does not result from a distinction in the essential principles of the soul, nor from a different kind of soul, but from the various co-aptation of souls to bodies, because this soul is adapted to this and not to that body, and that soul to another body, and so on. And this co-aptation remains in the soul even after the body has perished, even as the soul's substance remains through being independent of the body in the point of being. For the soul according to its substance is the form of the body, else it would be united to the body accidentally, and consequently the union of body and soul would result in one thing not essentially but accidentally. Now it is as forms that souls need to be adapted to their bodies. Therefore it is clear that these same various coaptations remain in separated souls, and consequently the plurality of souls remains also.

The third argument given above has been the occasion for some who held the world to be eternal, to fall into various strange opinions. For some granted the conclusion absolutely, and said that human souls perish altogether with their bodies. Others said that of all souls there remains some one thing separate that is common to all, namely the active intellect according to some, or besides this the possible intellect, according to others. Others however held that souls remain in their multitude after bodies, but lest they should be compelled to admit an infinite number of souls, they said that the same souls are united to different bodies after a certain lime. This was the Platonists' opinion, of which we shall treat further on. Others again, avoiding all the above statements, said that it is not impossible for separate souls to be actually infinite in number. Because in things not ordered to each other to be actually infinite is to be infinite accidentally, and they hold that there is no reason not to admit this. This is the opinion of Avicenna and Algazel. We do not find it expressly stated by Aristotle to which of these opinions he adhered, although he holds explicitly the eternity of the world. The last however of the above opinions is not inconsistent with the principles laid down by him. For in 3 Phys. and i Coel. et Mund., he proves that the actually infinite is impossible in natural bodies, but not in immaterial substances. Nevertheless it is certain that this question offers no difficulty to those who profess the Catholic faith, since they do not admit the world to be eternal.

Again, if the soul remain after the destruction of the body, it does not follow that it must have been accidentally united to it, as the fourth argument concluded. For an accident is described as that which may be present or absent without the corruption of the subject composed of matter and form. Now, if this be referred to the principles of the composite subject, it is found to be untrue. For it is clear that primary matter is not subject to generation and corruption, as Aristotle proves (i Phys.).' Wherefore it remains in its essence when the form departs. And yet the form was united to it not accidentally but essentially, since it was united to it in one being. Likewise the soul is united to the body in one being, as we proved above. Wherefore, though it survive the body, it is united to it essentially and not accidentally. That primary matter does not remain actually after the form except in respect of the act of another form, whereas that the human soul remains in the same act, is due to the fact that the human soul is form and act, whereas primary matter is a being in potentiality.

As to the statement put forward in the fifth argument, that no operation can remain in the soul when separated from the body, we say that it is false; since those operations remain which are not exercised through organs. Such are to understand and to will. But those operations do not remain which are performed through bodily organs, such as the operations of the nutritive and sensitive powers.

It must be observed, however, that the soul understands in a different way when separated from the body and when united to it, even as it has a different mode of existence: because a thing acts according as it is. For although the being of the soul while united to the body, is absolute and independent of the body, nevertheless the body is the lodging as it were and the subject that receives it. Wherefore in consequence its proper operation, which is to understand, though not depending on the body as though it were performed through a bodily organ, has its object in the body, namely the phantasms. Hence, as long as the soul is in the body, it cannot understand without a phantasm; neither can it remember except through the powers of cogitation and memory, by which the phantasms are prepared, as stated above. For this reason understanding, as regards this mode, as also remembering, is destroyed when the body perishes. On the other hand the separated soul has its being apart from the body. Wherefore neither will its operation, which is to understand, be performed in dependence upon certain objects existing in bodily organs, which are the phantasms; but it will understand by itself after the manner of substances wholly separate from bodies as to their being, of which we shall speak further on. From which substances, moreover, as from things higher than itself, it will be able to receive a more abundant inflow so as to understand more perfectly. We have a sign of this in the young. For the soul, the more it is withdrawn from being occupied about its own body, is rendered more apt to understand certain higher things: wherefore the virtue of temperance, which withdraws the soul from bodily pleasures, above all makes men apt in understanding. Moreover, men while asleep and not using their bodily senses, and when there is no disturbance of the humours or vapours to hinder them, are influenced by higher beings so as to perceive certain future things that surpass the purview of human reasoning: and this is much more the case with those who are in a faint or an ecstasy; forasmuch as they are the more withdrawn from the senses of the body. Nor does this happen unreasonably: because, since the human soul, as shown above, is on the boundary line of corporeal and incorporeal substances, as though it were on the horizon of eternity and time, by withdrawing from the lower world it approaches to the higher. Wherefore when it shall be wholly separated from the body, it will be perfectly likened to separate substances as to the manner of understanding and will receive their influence abundantly.

Accordingly, though our act of understanding as regards its mode in the present life ceases when the body perishes, another and higher mode of understanding will take its place.

Remembrance however, since it is an act performed through a bodily organ, as Aristotle proves in his book De Memoria et Reminiscentia, cannot remain in the soul after the body, unless remembrance be taken equivocally for the understanding of those things which the soul knew before: for the soul must needs remember what it knew in life, since the intelligible species are received indelibly into the possible intellect, as we have shown above.' With regard to the other operations of the soul, such as to love, to rejoice, and the like, we must beware of equivocation. Because sometimes they are taken for passions of the soul: and thus they are acts of the sensible appetite in respect of the irascible and concupiscible faculties, together with a certain bodily transmutation. And thus they cannot main in the soul after death, as Aristotle proves in his book De Anima. But sometimes they are taken for a simple act of the will, that is without any passion. Wherefore Aristotle says in the seventh book of Ethics that God rejoices by one simple operation, and in the tenth book that in the contemplation of wisdom there is wonderful pleasure, and in the eighth book, he distinguishes the love of friendship from the love that is a passion. Now since the will is a power that uses no organ, as neither does the intellect, it is clear that these things, in so far as they are acts of the will, remain in the separated soul.

Hence it cannot be concluded from the foregoing arguments that man's soul is mortal.