Cartesian dualism, the possibilities we all naturally believe in, namely that other people are not Zombies, and not Mutants, are themselves unverifiable!
Cartesian Dualism: There are 2 kinds of substance: the material and the mental. The material cannot think, and the mental has no place in space. This provides a way for the soul to outlive the body, as their properties don't need to match, allowing for an immortal soul. A branch of substance Dualism.
