The reason why some find it so hard to acknowledge consciousness, free will and thus Dualism lies in the inescapable supernatural consequences of such an acknowledgement, especially the One of them.
Philosophically, it's such an astonishingly (or frighteningly*, for some) straightforward process: the moment you acknowledge your spirit, your intellect takes off and flies to God.
*You barely have time to think; and some - in their pride, stupidity, stubbornness or God knows what - would rather procrastinate intellectually in Hell than move thier prejudices, fears or ambitions out of their intellect's way and let it draw the conclusion and reach God.
