CT 87: The Possible Intellect and the Agent Intellect as Residing in the Essence of the Soul

So we’ve shown that each man has one possible intellect and one agent intellect, and that these things are united to man as form. Consequently, says Thomas,

Since the agent intellect and the possible intellect are united to us as form, we must acknowledge that they pertain to the same essence of the soul.

I do not understand what he means by “the same essence of the soul.” The essence of something is what it is. The essence of a dog is to be a dog. The essence of a man is to be a rational animal. Does a man’s soul have its own essence apart from the essence of a man? But let’s move on. Thomas then says,

Whatever is formally united to another thing, is united to it either in the manner of a substantial form or in the manner of an accidental form. If the possible intellect and the agent intellect were united to man after the fashion of a substantial form, we would have to hold that they share in the one essence of that form which is the soul, since one thing cannot have more than one substantial form.

Right. If a man’s intellect is part of his substantial form, then it part of his soul, for his soul is his substantial form.

On the other hand, if they are united to man after the fashion of an accidental form, neither of them, evidently, can be an accident of the body. Besides, the fact that their operations are performed without a bodily organ, as we proved above, shows that each of them is an accident of the soul. But there is only one soul in one man. Therefore the agent intellect and the possible intellect must inhere in the one essence of the soul.

In other words, the agent and possible intellect are united with the soul either substantially or accidentally, not with the body as such.

Furthermore, every action that is proper to a species proceeds from principles that emanate from the form which confers the species. But the action of understanding is an operation proper to the human species. Therefore the agent intellect and the possible intellect, which are principles of this action, as has been shown, emanate from the human soul, whence man has his species. However, they do not issue from the soul in such a way as to extend to the body, because, as we have said, the operation in question takes place independently of a bodily organ. Since, therefore, action pertains to the same subject as does potency, the possible intellect and the agent intellect inhere in the one essence of the soul.

I am rational because I am a man, a rational animal. It is part of being human, part of the very definition of being human, to be rational. It is my intellect that makes me rational: I must necessarily have one. But the intellect is immaterial; so it must “inhere in the one essence of the soul.”

There’s clearly a distinction I’m missing here; I don’t understand why Thomas insists on “inhere in the one essence of the soul” rather than just “inhere in the soul”.

2 Responses to “CT 87: The Possible Intellect and the Agent Intellect as Residing in the Essence of the Soul”

  1. Brandon says:

    I’m not sure I fully understand everything that is going on here either, but part of the background in these sections is that different philosophers (Islamic as well as Christian philosophers are in view) held different views about how the agent intellect and the potential intellect were related to each other. So St. Thomas has to argue that each human soul has its own potential intellect, that each one has its own agent intellect, that the agent intellect is not something external to the human soul (like God or an immaterial intelligence other than human beings) &c. I think the point in this section is that not only do we have our own agent intellect and our own potential intellect; we have them both together as part of our human soul (cf. the first sentence of the next section, which suggests that the union is the big conclusion he wants people to draw). We can’t possess them as distinct substantial forms, because then we’d be two completely different substances; and if we had them as something like accidental forms, they can’t be like accidental forms belonging to the body, and they can’t be like accidental forms belonging to different souls. So they both must belong essentially to one and the same soul.

    So in other words I think it’s a long, complex argument for a conclusion that would usually seem pretty obvious to us, but for which St. Thomas has to provide an actual argument because of the different views about how the agent intellect and potential intellect are related to each other. (Some people thought that the agent intellect was something completely separate from any particular human being, &c.)

  2. Yeah, I looked ahead a little bit after I wrote this, and I think you’re right. The subsequent chapter titles are:

    The Way These Two Faculties Are United in the Same Essence of the Soul
    Radication of All the Faculties in the Essence of the Soul
    Unicity of the Soul
    Arguments Advanced to Show a Multiplicity of Souls in Man
    Refutation of the Preceding Objections

    In short, all of a man’s faculties are united in the one soul, which is his and no one elses, and he’s only got the one.

    No I just need to read through it all.