CT 91: Arguments Advanced to Show A Multiplicity of Souls in Man

Thomas once again departs from the script with this chapter; having asserted that each man has a single soul, he’s giving the objections in this chapter and the answers to the objections in the next.  If there’s no feeling of closure in this post, blame Thomas, not your humble scribe.

Thomas begins,

Certain considerations seem opposed to our doctrine. In the first place, specific difference is to genus what form is to matter. Animal is the genus of man, and rational is the difference that makes man what he is. Accordingly, since animal is a body animated by a sensitive soul, it seems that a body animated by a sensitive soul is still in potency with respect to the rational soul. Thus the rational soul would be distinct from the sensitive soul.

Hmmm.  Form makes matter what it is; matter that does not possess a particular form (but can) is in potency with respect to that form. My son can dye his hair blue, but he has not yet done this; his hair is blue in potency.  Just as blueness can be added to my son’s hair to make it blue in act, the specific difference “rational” can be added to the genus “animal” to make it “man” in act.  Thus, “animal” is in potency with respect to “rational”…and rationality is an accident added to an animal substance.  Hence, the rational soul must be distinct.  The error, I think, is that the objector is using an invalid analogy.  We’ll see.

Moreover, the intellect does not possess a bodily organ. But the sensitive and nutritive powers do possess bodily organs. Hence it seems impossible for the same soul to be both intellectual and sensitive, because the same thing cannot both be separated and not separated from another thing.

That’s clear enough.  But must two things which are “not separated” be coextensive?  I don’t see why they should be.

Furthermore, the rational soul is incorruptible, as was shown above. On the other hand, the vegetative and the sensitive souls are corruptible, as they are acts of corruptible organs. Therefore the rational soul is not the same as the vegetative and the sensitive souls, for the same thing cannot be both corruptible and incorruptible.

The problem here, I think, is the lack of a distinction between souls on the one hand and faculties on the other.  The vegetative soul has the vegetative faculty: plants can take in nutrition and grow.  The sensitive soul has the vegetative faculty and the sensitive faculty.  The rational soul has the vegetative, sensitive, and rational faculties.

Thus, it’s not that man has a vegetative soul, a sensitive soul, and a rational soul; rather, he possesses all three faculties in one rational soul.  The first two faculties require corruptible organs, that is, material organs that can die; the last does not.

Besides, in the generation of man the life conferred by the vegetative soul appears before the fetus is observed to be an animal from its sense activity and motion; and this same being is discerned to be an animal through its sense activity and movement before it has an intellect. Therefore, if the soul by which the fetus first lives the life of a plant, then the life of an animal, and thirdly the life of a man, is the same, it would follow that the vegetative, sensitive, and rational principles come from an outside source, or else that the intellectual soul arises from the energy in the semen. Both of these alternatives are inadmissible. On the one hand, since the operations of the vegetative and sensitive soul are not exercised apart from the body, their principles cannot be without a body. On the other hand, the operation of the intellectual soul is exercised without a body; and so, apparently, no bodily energy can be its cause. Therefore the same soul cannot be vegetative, sensitive, and rational.

One can argue with St. Thomas’ notion of fetal development, but I’ll slide past that.  The argument here appears to be that since the vegetative and sensitive souls require bodily organs, they are caused by the body; and yet, being immaterial, the rational soul, or intellect, cannot be caused by the body; and since they have two distinct causes, they must be two distinct things.  But the body is not the principle of the soul; the soul is the principle—the form—of the body. 

I suppose you could think of this chapter as a sort of quiz, with essay questions.  We’ll see how I did when I blog the next chapter.

Comments are closed.