In his sixth meditation must return to the doubts he raised in his first meditation. In this last section of his sixth meditation he deals mainly with the mind-body problem; and he tries to prove whether material things exist with certainly. In this meditation he develops his Dualist argument; by making a distinction between mind and body; although he also reveals their rather significant relationship. Primarily he considers existence of the external world and whether our experience hold knowledge of this world or whether this knowledge is merely an illusion. He makes it quite clear how mislea