Chapter 80 — 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, (Ch. 75.) it follows that when the bodies are destroyed, the souls cannot remain in their multitude. Therefore, 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. (Cf. cc. 73, 76.)

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 (Cc. 50–51.) 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 that 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 the body. For if the world exists from eternity, movement is from eternity; 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 that souls do not remain many after death if the world is eternal.

Again. That which accrues to a thing and departs from it without the latter being corrupted accrues to it accidentally, (Porphyry, Isagoge, ch. 5.) or 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, perfected by the soul, is nourished and increased, and from which is determined the seed for 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 colors to the sight. (Cf. Aristotle, On the Soul 3.5, 430a10–16; 3.7, 430b26–431a4.) Therefore, as the sight cannot see without colors, 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 without phantasms, (Aristotle, On the Soul 3.7, 431a15–16.) and that it understands nothing without the passive intellect, (Aristotle, On the Soul 3.7, 431b2–9.) which he calls the cogitative power, and which is corruptible. For this reason he says that man’s act of understanding is corrupted when something within him is corrupted, (Aristotle, On the Soul 1.4, 408b22–25.) namely, the phantasm or the passive intellect. And it is stated in On the Soul 3 (Aristotle, On the Soul 3.5, 430a17–18.) 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.