ABSTRACT
Materialism is a doctrine in metaphysics. It is a claim about what there is and what it is like. The knowledge argument turns on an epistemological claim, namely, that no story about our world told purely in physical terms —the kind of terms that appear in the materialists’ or physicalists’ preferred account of the world and its nature-could enable one to deduce the phenomenal nature of psychological states. How is a doctrine in metaphysics supposed to be threatened by a doctrine about the impossibility of a certain sort of deduction?
