Knowing substance

One of the crucial elements of STA’s doctrine of the soul is his denial that the powers of the soul are its essence. This means that when we speak of the rational or intellectual soul we are naming it by a power that is really different from what the soul is. A human being is not a body unified to intellection, though this is easy enough to imagine (provided we make intellection a luminous smoke with cognitive power). Rather, intellection and human corporeality issue forth from some unknown reality with the power to actualize and unify both. We call it the rational soul not because it is reason, but as a sort of honorific.

STA clearly takes this question as foundational and very problematic. It’s the first question he treats of in the question of the powers of the soul, he raises an unusually long set of objections to his thesis, and his response is particularly strident and emphatic, with both of his supporting arguments introduced by saying “it is impossible that…”

There are signs, however, that STA has a difficult time giving a coherent response to the question. Consider his responses to arg. 1 and arg 7:

ad. 1 [K]nowledge and love as referred to the soul as known and loved, are substantially or essentially in the soul, for the very substance or essence of the soul is known and loved.

ad. 7 substantial forms, which in themselves are unknown to us, are known by their accidents; nothing prevents us from sometimes substituting accidents for substantial differences. [n.b. this claim is made explicitly about reason, not about purely material substances- ed.]

So do we know the substance of our own soul or not? To be fair, this is another question that STA treats at great length, but it’s not clear how even a lengthy response can do the work he needs it to do here.

I don’t know that there is any properly Thomistic answer to the question of the knowability of substance, which seems to be the general question which the problem of the soul brings into bright relief. St. Thomas (who is underappreciated for the things he refuses to talk about) seemed to take this general problem as something he would stay largely silent about.



  1. thenyssan said,

    April 7, 2015 at 6:31 am

    I backed into this uncertainty doing his ethics with my students. He leans heavily on substance:essential accidents::object:circumstances. If we give up on the knowability of substance entirely, I worry about the knowability of object of an act in ethics. Why aren’t objects simply reducible to bundles of circumstances? It makes me want to look back at the battles Pinckaers had over intrinsically evil acts.

    • April 7, 2015 at 9:52 am

      There are problems here that we have yet to have a good theory for. The Greeks were conflicted over whether the abstract/nature was more real than the soul/individual substance or vice versa (cf. the Plato of the Republic and of the Laws bk. 10), and Christianity added a new dimension and importance to individuals and persons (in fact, any orthodox Christology has to find something that “the person” adds something to mere individuality – but what is that? It still seems open.)

      We have yet to find a theory of the real that can satisfy the demands of intelligibility/ science and individuality/personhood/ history/narrative. I’m poking around and tinkering, but the field is still much as it ever was.

      • Socrates said,

        April 9, 2015 at 10:09 pm

        Are you aware of Xavier Zubruri’s concepts of “open essence” vs “close essence?”

        Christi pax.

  2. April 7, 2015 at 8:01 am

    What a great blog!

    Questions: so if one cannot know “substance”, is one stuck with the “phenomenon”? If “rational soul” is a name we give to something unknowable, aren’t we falling into nominalism?

    • April 7, 2015 at 9:45 am

      “Know” is too broad a term to deny of substance altogether – or even to deny of anything altogether. St. Thomas has a problem because he seems to be conflicted over whether a person’s own knowledge of himself is of his substance as such or of his substance as inferred from [essential?] accidents. He has a similar problem when he speaks of whether singulars are unknowable to us as such, or unknowable to us as material. Here he also seems to want to have it both ways.

      There’s too much to address in your comment to touch on in a single comment, I might parse it out over a few posts.

      • April 7, 2015 at 10:30 am

        I look forward to them!

        Also, I’ve linked from my blog to yours!


  3. Socrates said,

    April 9, 2015 at 10:32 pm

    It might be that we can’t know who we are completely: we might learn about aspects of the self, such as the intellect or the body, but not the whole.

    The first thought that came to my mind was G. K. Chesterton’s Introduction to the Book of Job:

    In it he makes an interesting observation:

    “He is willing to regard it as if it were a fair intellectual duel: “Gird up now thy loins like man; for I will demand of thee, and answer thou me” (38:3). The everlasting adopts an enormous and sardonic humility. He is quite willing to be prosecuted. He only asks for the right which every prosecuted person possesses; he asks to be allowed to cross-examine the witness for the prosecution. And He carries yet further the corrections of the legal parallel. For the first question, essentially speaking, which He asks of Job is the question that any criminal accused by Job would be most entitled to ask. He asks Job who he is. And Job, being a man of candid intellect, takes a little time to consider, and comes to the conclusion that he does not know.”

    The last sentence is particularly important, in my opinion. Chesterton seems to think that the soul is ultimately far more mysterious than the rest of Creation. This notion is further supported here:

    “Every man has forgotten who he is. One may understand the cosmos, but never the ego; the self is more distant than any star.
    Thou shalt love the Lord thy God; but thou shalt not know thyself.
    We are all under the same mental calamity; we have all forgotten our names. We have all forgotten what we really are. All that we call common sense and rationality and practicality and positivism only means that for certain dead levels of our life we forget that we have forgotten. All that we call spirit and art and ecstasy only means that for one awful moment we remember that we forget.”

    Just presenting some thoughts.

    Christi pax.

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