FIRST ARTICLE: THE SUBSISTENCE OF THE SEPARATED SOUL

The subsistence of the soul separated from the body is demonstrated by this principle: Every simple form that is intrinsically independent of matter (in its operation, its being, and in its production) subsists independently of matter and perdures after separation from the body. But the human soul is a simple form and is intrinsically independent of matter. Therefore the human soul subsists after the dissolution of its body.

The Averroists object that since the human soul is individuated by matter, or by its body, when it is separated from the. body it is no longer individuated, and hence nothing subsists except one soul for all men. Others went on to say that if the soul of St. Peter is saved, my soul is also saved, because after separation from the body my soul is not distinct from the soul of St. Peter.

Replying to the Averroists St. Thomas said that, just as the human soul has an essential (or transcendental) relation to the body of a man and not to that of a lion, so this human soul has an essential (or transcendental) relation to this particular body. And this relation remains in the soul even though the terminus of the relation no longer exists, and thus the separated soul remains individuated. If this relation were predicamental or accidental, like paternity, it would disappear with its terminus. But such is not the case with a non-accidental relation, which is founded directly on the very substance of the soul. In the same way the essential relation of the faculty of sight reaches out to a colored object even though all colored things should be destroyed. The individuation of the rational soul therefore depends on the body in its becoming but not in its being, and thus there can be no question of metempsychosis.[1326] The human soul cannot inform the body of a brute animal, nor can the soul of Socrates inform Plato's body; each soul preserves its relation to its body and in this way remains individuated.[1327]

If the human soul were united only accidentally to the body, this particular soul would have only an accidental relation to this particular body, and this relation would disappear when the terminus is destroyed, that is, when the body is dissolved. But this is not true since the human soul is united to the body by its very nature, and together with the body the soul constitutes a being that is one "per se", that is, one nature. Thus St. Thomas is always faithful to the principle of economy, according to which a question should not be explained by many principles if it can be explained by fewer principles. In this treatise, as in others, all the conclusions are deduced from a few exalted principles, and this makes for a greater unification of our science.

From the foregoing it follows that it is more perfect for the rational soul to be united to the body than to be separated from it, for this lowest intellect has for its proportionate object the lowest intelligible being, placed in the shadows of sensible being, and in order to know this kind of being the soul needs the senses, and therefore the body, which exists on account of the soul. Thus, "per se" the body is useful for the soul, although at times it may be a hindrance.[1328] The state of separation from the body, therefore, is preternatural for the soul;[1329] and the soul naturally desires to reinform its body, all of which is in full accord with the dogma of the general resurrection.[1330] The separated soul, however, cannot at will reassume its body, because it is the form of the body not by an action that is dependent on its will, but it is the form of the body by its nature. Operation follows being, and the soul does not have power over its own being; the being of both soul and body are under the power of God alone, and God alone can revive the body and He alone as the author of life can restore life to a corpse.[1331]