The materialist version of the mind/brain identity theory has met with considerable challenges from philosophers of mind. The author first dispenses with a popular objection to the theory based on the law of indiscernibility of identicals. By means of discussing the vexatious problem of phenomenal qualities, he explores how the debate may be advanced by seeing each dualist and monist ontology through the lens of an evolutionary epistemology. The author suggests that by regarding each ontology as the core of a (...) scientific research programme, each of these logically irrefutable hypotheses can be tested rationally. (shrink)