On the senses and the mind

A further problem with the imagined Cartesian dualist response …. Is that it begs the question against the Aristotelian insofar as it assumes that the perceptual and cognitive states of subjects of experience can entirely float free of the body. From the Aristotelian point of view, that is not the case, even given that the human intellect is incorporeal. For one thing, perceptual experience is corporeal, presupposing sense organs and brain activity. For another thing, even cognition requires, in the ordinary case, brain activity as a necessary condition, even if it is not a sufficient condition. … If we were entirely incorporeal, we would essentially be angels, having our knowledge in a single act and without relying on perceptual experience. The Cartesian notion of res cogitans is really the notion of an angelic intellect, not a human one. Hence, from the Aristotelian point of view, to establish that there is a succession of perceptual and cognitive states in the subject of experience just is to establish that that subject is corporeal and thus that the way in which it manifests actuality and potentiality is in part by being a composite of form and matter. (Edward Feser, Aristotle's Revenge, 93)

Does the mind require senses to function? Is corporeality necessary for thinking? According to Edward Feser, corporeality is necessary for human thinking and learning, whereas non-corporeal thinking is angelic and having "knowledge in a single act and without relying on perceptual experience." Yet in Feser's steps of arguments one can see many flaws and false assumptions present.

The first flaw is the assumption that perceptual experience is corporeal. According to Feser, to perceive something one must have a body. But in the Aristotelian scheme, humans are hylomorphic (where the soul is the form and the body the matter). Since for the Christian, during the period between the first death and Christ coming back, the souls of believers will be with God while the body remains in the grave (c.f. Phil. 1:21, 1 Cor. 15:23), how is this possible if humans are hylomorphic? In this glorified but not fully recreated existence, can the soul perceive God's love for him? It would seem for the Christian that the answer should be yes. And if that is true, then Feser's assumption here is false, for the Christian soul that is non-corporeal following the first death can indeed have perceptual experiences.

Feser's second assumption is that cognition requires brain activity. But that confuses correlation with causation. If as we have argued that the non-corporeal soul can have perceptual experiences, then certainly cognition does not require brain activity as a necessary condition. Lastly, Feser continues smuggling in his idea that an object must have actuality and potentiality, but that is almost expected by now.

Since that is the case, it is not true from a Christian perspective that the senses are needed for the mind to function. The "Cartesian notion of res cogitans" is therefore not an angelic way of knowing and the fact that there is a succession of perceptual and cognitive states does not imply anything about the thinking subject or the nature of things.