The knowledge argument is something that is both an ideal for philosophy and yet
surprisingly rare: a simple, valid argument for an interesting and important conclusion, with
plausible premises. From a compelling thought-experiment and a few apparently innocuous
assumptions, the argument seems to give us the conclusion, a priori, that physicalism is
false. Given the apparent power of this apparently simple argument, it is not surprising that
philosophers have worried over the argument and its proper diagnosis: physicalists have
disputed its validity, or soundness or both; in response, non-physicalists have attempted to
reformulate the argument to show its real anti-physicalist lesson
