Questions Addressed to Dualists

I once addressed these words to a friend and colleague who advocates hylomorphic (hylemorphic) dualism:

How do we know that physical organs are only capable of apprehending particulars? What incontrovertible proof do we have that intellects (of the Thomistic caliber) even obtain [exist]? I admit that an intellect qua a power of the soul is logically possible [there's no logical contradiction in the idea itself]. However, I am not convinced that such a faculty is factually possible. So I guess my first line of attack would be to question the existence of the intellect, in the relevant sense we're discussing. Secondly, I would argue that what has been called "intellect" is really nothing more than a higher-order process of the brain: intellection is a biological phenomenon. The brain consequently makes it possible for us to have the facility for grasping what appear to be [abstract] universals.

I have slightly edited some of this message to promote understanding of its contents.

Regards,

Edgar