Summary Against Modern Thought: The immortality of the soul, Part I

This may be proved in three ways. The first...
This may be proved in three ways. The first…
See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.

We’re finally at the immortality of the soul! Well, the start of the proof, anyway. This week is long, but it’s surprisingly easy given what we’d done thus far.

Chapter 79 That the human soul does not perish when the body is corrupted (alternate translation) We’re still using the alternate translation.

1 From what has been said, therefore, it can be clearly shown that the human soul is not corrupted when the body is corrupted.

2 For it was proved above that every intellectual substance is incorruptible. But man’s soul is an intellectual substance, as was shown. It therefore follows that the human soul is incorruptible.

Notes Where this incorruptible soul reposits is not here proved: like many metaphysical arguments, this one is a proof of existence; it is not a constructive proof. You cannot make your own soul! But you procreate new ones. (Forgive me).

3 Again, no thing is corrupted with respect to that wherein its perfection consists, for mutations in regard to perfection and corruption are contrary to one another. The perfection of the human soul, however, consists in a certain abstraction from the body. For the soul is perfected by knowledge and virtue, and it is perfected in knowledge the more it considers immaterial things, the perfection of virtue consisting in man’s not submitting to the passions of the body, but moderating and controlling them in accordance with reason. Consequently, the soul is not corrupted by being separated from the body.

Notes The soul “is perfected in knowledge the more it considers immaterial things”. Get your mind out of the gutter! This kind of perfection used to be well known in (what used to be called) higher education.

4 Now, it may be said that the soul’s perfection lies in its operational separation from the body, and its corruption in its existential separation therefrom. Such an argument misses the mark, for a thing’s operation manifests its substance and its being, since a thing operates according as it is a being, and its proper operation follows upon its proper nature. The operation of a thing, therefore, can be perfected only so far as its substance is perfected. Thus, if the soul, in leaving the body, is perfected operationally, its incorporeal substance will not fail in its being through separation from the body.

Notes But you lose the chance to further perfect your soul when you hand in your dinner pail. Plan accordingly.

5 Likewise, that which properly perfects the soul of man is something incorruptible; for the proper operation of man, as man, is understanding, since it is in this that he differs from brutes, plants, and inanimate things. Now, it properly pertains to this act to apprehend objects universal and incorruptible as such. But perfections must be proportionate to things perfectible. Therefore, the human soul is incorruptible.

6 Moreover, it is impossible that natural appetite should be in vain. But man naturally desires to exist forever.

This is evidenced by the fact that being is that which all desire; and man by his intellect apprehends being not merely in the present, as brute animals do, but unqualifiedly.

Therefore, man attains perpetual existence as regards his soul, whereby he apprehends being unqualifiedly and in respect of every time.

7 Also, the reception of one thing in another accords with the recipient’s manner of being. But the forms of things are received in the possible intellect according as they are actually intelligible; and they are actually intelligible according as they are immaterial, universal, and consequently incorruptible. Therefore, the possible intellect is incorruptible. The possible intellect, however, is part of the human soul, as we proved above. Hence, the human soul is incorruptible.

8 Then, too, intelligible being is more permanent than sensible being. But in sensible things that which has the role of first recipient, namely, prime matter, is incorruptible in its substance; much more so, therefore, is the possible intellect, which is receptive of intelligible forms. Therefore, the human soul, of which the possible intellect is a part, is also incorruptible.

9 Moreover, the maker is superior to the thing made, as Aristotle says. But the agent intellect actualizes intelligibles, as was shown above. Therefore, since intelligibles in act, as such, are incorruptible, much more will the agent intellect be incorruptible. So, too, then, is the human soul, whose light is the agent intellect, as we have previously made clear.

10 Again, a form is corrupted by three things only: the action of its contrary, the corruption of its subject, the failure of its cause; by the action of a contrary, as when heat is destroyed by the action of cold; by the corruption of its subject, as when the power of sight is destroyed through the destruction of the eye; by the failure of its cause, as when the air’s illumination fails through the failure of its cause, the sun, to be present.

But the human soul cannot be corrupted by the action of a contrary, for nothing is contrary to it; since, through the possible intellect, it is cognizant and receptive of all contraries. Nor can the human soul be destroyed through the corruption of its subject, for we have already shown that it is a form independent of the body in its being. Nor, again, can the soul be destroyed through the failure of its cause, since it can have no cause except an eternal one, as we shall prove later on. Therefore, in no way can the human soul be corrupted.

Notes The “it can have no cause except an eternal one” is the constructive part of the proof.

11 Furthermore, if the soul perishes as the result of the body’s corruption, then its being must be weakened through the debility of the body.

But if a power of the soul is weakened for that reason, this occurs only by accident, namely, in so far as that power has need of a bodily organ.

Thus, the power of sight is debilitated through the weakening of its organ—accidentally, however.

The following considerations will make this point clear. If some weakness were attached to the power through itself, it would never be restored as the result of the organ’s being restored; yet it is a fact of observation that, however much the power of sight may seem to be weakened, if the organ is restored, then the power is restored. That is why Aristotle says, in De anima I [4], “that if an old man were to recover the eye of a youth, he would see just as well as the youth does.”

Since, then, the intellect is a power of the soul that needs no organ—as we proved above—it is not weakened, either through itself or accidentally, by old age or any other bodily weakness. Now, if in the operation of the intellect fatigue occurs, or some impediment because of a bodily infirmity, this is due not to any weakness on the part of the intellect itself, but to the weakness of the powers which the intellect needs, namely, of the imagination, the memory, and the cogitative power. Clearly, therefore, the intellect is incorruptible. And since it is an intellective substance, the human soul likewise is incorruptible.

Notes And the “imagination, the memory, and the cogitative power” are, as all known, often corrupted.

12 This conclusion also comes to light through the authority of Aristotle. For he says in De anima I [4] that the intellect is evidently a substance and is incapable of being destroyed. And it can be inferred from what has been said already that remark of Aristotle’s cannot apply to a separate substance that is either the possible or the agent intellect.

13 The same conclusion also follows from what Aristotle says in Metaphysics XI [3], speaking against Plato, namely, “that moving causes exist prior to their effects, whereas formal causes are simultaneous with their effects; thus when a man is healed, then health exists,” and not before—Plato’s position, that the forms of things exist prior to the things themselves, to the contrary notwithstanding.

Having said this, Aristotle adds: But we must examine whether anything also survives afterwards. “For in some cases there is nothing to prevent this—the soul, for example, may be of this sort, not every soul, but the intellect.” Since Aristotle is speaking of forms, he clearly means that the intellect, which is the form of man, remains after the matter, which is the body.

14 It is also clear from these texts of Aristotle that, while he maintains that the soul is a form, he does not say it is non-subsistent and therefore corruptible—an interpretation which Gregory of Nyssa attributes to him. For Aristotle excludes the intellective soul from the generality of other forms, in saying that it remains after the body, and is a certain substance.

Notes The next paragraphs all rely on the Bible and may be skipped by heathens and heretics.

15 The doctrine of the Catholic faith is in agreement on these matters. For in the work On the Teachings of the Church there is this statement: “We believe that man alone is possessed of a subsistent soul, which continues to live even after divesting itself of the body, and is the animating principle of the senses and powers; nor does the soul die with the body, as the Arabian asserts, nor after a short period of time, as Zeno would have it, because it is a living substance.”

16 This eliminates the error of the ungodly, in whose person Solomon says: “We are born of nothing, and after this we shall be as if we had not been” (Wis. 2:2); and in whose person again Solomon says: “The death of man and of beasts is one, and the condition of them both is equal: as man dies, so they also die: all things breathe alike, and man has nothing more than beast” (Eccle. 3:19). For

Solomon clearly is not speaking in his own person but in that of the godless, since at the end of the book he adds in a decisive manner: “Before the dusts return into its earth, from whence it was, and the spirit returns to Him Who gave it” (Eccle. 17:6-7).

17 Furthermore, there are myriad passages of sacred Scripture which proclaim the immortality of the soul.


  1. DG

    I agree with Aquinas that the soul or mind survives bodily death – we already have plenty of evidence for that from near death experiences. However, I am inclined to think that his mixture of Aristotle’s hylomorphism with the Christian view of the immortality of the soul is not something that can be reconciled or at least is very problematic at best. For one, Aristotle does make statements in the De Anima suggesting that the soul dies along with the body as he states “Hence…the soul cannot be without a body, while it cannot be a body; it is not a body but something relative to a body…From all this follows that the soul is an actuality or formulable essence of something that possesses a potentiality of being ensouled” De Anima, Bk 2, Chapt. 2: 19-29. It’s not clear that Aristotle believed in an afterlife and many statements of his about the soul seem to imply that the soul is not immortal. After all, Aristotle often describes the unity of body and soul as a unity of ONE substance and not TWO substances.
    Moreover, how do you account for the Aristotlian view that the soul is individualized by the body? And even Aquinas says the body gives the soul its unique individuality. If there is an afterlife what continues to individualize the soul when the body is no longer there? Doesn’t hylomorphism require that the body individulize the soul as its form? If so, then how is an afterlife possible with hylomorphism?
    I would advocate some form of substance dualism and not some confused hylomorphist view, to account for the immortality of the soul.

  2. Ye Olde Statistician

    DG: Keep in mind that for Aristotle, the soul was not restricted to the rational soul alone. It included the vegetative and sensitive souls as well. And Aquinas gladly agreed that these powers also perished when the human perished: there was no marrying or giving in marriage in the afterlife because the reproductive power belongs properly to the vegetative powers of the soul, not to the rational powers and are tied inextricably to material organs. You know which organs they are. But the intellect and will are not tied to any organ. There is no organ that “senses” dog, only organs that sense this dog or that dog (i.e., particulars). Thus, there is no reason to suppose that the power of abstraction of universals must perish when the material organs perish.

    But this is somewhat like the ‘stub’ of a human being, and that may be why the Church has always taught the “resurrection of the body,” i.e., that the rational soul will at some point be re-united with a new, somehow ‘glorified’ body. Some people think this glorified body will be a computer into which their mind has been downloaded, but… everyone to his own eschatology.

  3. DG

    @ Statistician:

    Glad somebody responded! For a while I thought no one was going to respond to my comment.

    Ok, well of course Aristotle clearly thought that every living thing has a “soul” because the soul for him is the form of a living body or abstract state of being alive that’s individuated by the body and so every living thing, by his definition, would have a soul.

    My point is that if hylomorphic principles of matter and form are used to describe the relationship between body and soul then an afterlife becomes problematic because if the soul is treated as a “form” or abstract condition of being alive that has to be made an INDIVIDUAL SOUL BY THE BODY then this seems to imply that the soul would die along with the body. Because forms in the world can only exist and be instantiated when you have some material to instantiate them given the hylomorphist paradigm. These abstract “forms” of chairness, dogness, triangleness, for instance, need some material to be made into individual chairs, dogs, and triangles etc. So if the body is needed to individuate the soul as Aristotle and Aquinas held, then the soul should cease to exist once the body dies out because then you longer have any material to individualize or instantiate your “form” viz., the soul.

    And we can argue whether Aristotle really believed in an afterlife – I tend to think that he didn’t but that’s beside the point. The point is that hylomorphism fails to consistently account for an afterlife whether Aristotle personally believed it or not. And because hylomorphism makes an afterlife or disembodied consciousness impossible then I have sufficient reason to reject it as a philosophical account of the soul.

    I would endorse substance dualism or at least some philosophical theory that says that mind or the conscious self is an immaterial substance distinct from the body and brain if you want to have adequate support for an afterlife. After all, if there’s afterlife then that implies that the mind can exist apart from the brain thus entailing that the mind is a substance or conscious subject in its own right.

  4. Ye Olde Statistician

    Substance dualism, a la Descartes, brings up the interaction problem. How is it that when the res extensa turns right at the corner, the mens rea turns right with it?

    #79 is only the first paragraph of a fair number in series:
    I think Dr. Briggs should have taken entire series of paragraphs from Contra gentiles and boiled them together rather than to have taken them a paragraph at a time with a week in between. Too many trees for the forest. It’s too easy to lose the thread of an argument that way. We have already seen here several commentators falling back reflexively to stock objections that were answered months ago(!) either because they have forgotten, failed to understand, or never bothered to read the earlier posts.

    These same matters are addressed in a more concise form in the Summa theologica, a digest written for theology students, organized somewhat differently from the Summa contra gentiles. There is a very nice boiled-together explanation of the ST (curiously also done by a (bio)statistician) with the parallel Quaestion found here:

    The common teaching of the time was that the soul is the form of the body; therefore it seems to make no sense to speak of the soul as being subsistent, a this-something (hoc aliquid), since it is the form-matter composite that is the this-something, not the soul on its own. Aquinas answers that we can think of something like a hand as a subsistent thing, a this-something, that is a part of something that is a complete subsistent thing. The human soul is subsistent in the sense that the hand is subsistent as a distinguishable part of some greater whole; but it is not subsistent in the sense of being complete in itself. Likewise, when we think of how the operations of a part of the body (such the eye seeing) relate to the operations of the whole we should think in terms of the whole operating by means of the operations of the parts. The human sees by means of the eye; the human understands by means of his soul.

    The blogger also does a good job of reminding the readers about terms that had different meanings back then compared to their modern descendents.

    And also here:
    same url but …2014/01/question-89-separated-souls-cognition.html

    St. Thomas’ Commentary in his tract on I Corinthians writes 15 (lecture 2, para. 924) “…but the soul, since it is part of man’s body, is not an entire man, and my soul is not I,”
    as discussed in an essay here: also relevant to your question.

  5. DG

    Hi there Statistician!

    Well, I am not a cartesian dualist since I depart from several premises in Descartes’ perspective of the soul, but I do think that the human being is a unity of two substances of body and mind as any substance dualist would say.

    I also find it odd that a Thomist would make that interaction objection to Descartes considering that if an immaterial substance cannot interact with a physical substance, then this would seem to imply that God cannot interact with the material world. God is an immaterial entity like the human soul so if it’s impossible for a soul to interact with a body then shouldn’t it be impossible for other immaterial beings like God to interact with the material world? Moreover, Aquinas implies that the mind or at least certain aspects of the mind are a distinct substance apart from the body when admits of an afterlife. How is the interaction problem only a problem for Descartes but not for this “subsistent form” or hylomorphic intellectual substance in Aquinas?

    But besides all this, I have yet to see why if the soul is the form of the body in the sense that Aristotle talks about then how is an afterlife possible with hylomorphism? I’m sorry but I don’t find Aquinas’ hand analogy helpful considering that if you cut off your hand then the hand eventually dies. So the soul is a part of the full human being but what is going to prevent it from dying out like that separated hand when one part of the individual -the body- dies out?

    The other thing is that there seems to be a confusion of terms when defining the soul in Thomistic hylomorphism. For one, when Aquinas admits that the soul is capable of surviving bodily death, the soul then is treated as an immaterial substance of mind like in Descartes. But when he speaks of soul being instantiated by the body, he treats the soul as an abstract form or abstract condition of being alive that’s individuated by the body – which he inherits from Aristotle. Well, is the soul only a form, presumably an abstract form of being alive that’s instantiated by some material or is the soul a mental substance added on par to the body? And if the soul is a mental substance then how is a physical object going to “individuate” the soul? Are souls immediately created by the Deity anyway? Maybe you can clarify some of this for me.

  6. How can a soul think without a brain, see without eyes, and hear without ears?

  7. Ye Olde Statistician

    “Think” is too generic. There is more than one kind of thinking. Some of it may require time. A living body is embedded in time and uses its brain for some kinds of thinking, such as imagination. Other kinds of thinking, such as intellection do not appear to require a material organ since there is no material object that corresponds to the object of conception and therefore no “thing” to be sensed.

    Souls cannot “see” or “hear” without “eyes” or “ears,” as Aquinas noted a long time ago. (Also “eye” and “ear” must be understood in the extended sense to include the entire train of nerves and neurons involved in sight and hearing.) However, intellective beings supervene intellectively on that which they sense, so there is an intellective component even to sensed objects. That is, we not only see black marks on the screen, but we also understand the meanings of those black marks, which exist nowhere in the sensed object. For example, the black lines that comprise the sign H can mean different things to an English-reader, a Russian-reader, or a Cherokee-reader. Or for that matter to a reader of street signs or chemical formulae. No matter how carefully you measure the lengths and widths of the lines, the thickness of the strokes, the candlepower of their brightness, or their resistance to the electrical fluid, no materialistic measurement will reveal their meaning.

  8. Ye Olde Statistician

    DG: this would seem to imply that God cannot interact with the material world.

    God does not inter-act with the material world. He acts on the material world. Interaction ain’t in it. In fact, the interaction “problem” is also a problem for naturalists. How does a falling rock interact with gravity? How does energy interact with the bodies it moves?

    “How does an armadillo interact with modus tollens, or a cornfield interact with a paint? Still, there are arguments that turn on affirming there are armadillos, and paintings inspired by cornfields. Causality is not interaction.”

    Some discussions are here:

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