In this review of Consciousness, I learned that materialist theories of consciousness are out of favor. Everyone is back to dualism of one sort or another. In significant part because of "the knowledge argument, which says (to put it very simply) that materialism is false because it is possible to know all the physical facts and yet not know all the facts." Or, "the knowledge argument rests on the intuition that Mary learns something on coming out, that is, that she comes to know something that she did not before. It is this intuition (or rather this intuition combined with the intuition that she knew everything physical)". Mary knows all the physical facts and then goes out to look at an apple and thereby knows something new, seems to be the idea. I wonder about the intuitions here, partly because I just don't share them (I don't think she does have new knowledge, he just has an experience), but also because I wonder the argument is that ties consciousness and knowledge together for the knowledge argument. I am sure there are well-developed and clever arguments in the background (it is just a review, after all and does refer to key pieces of the literature - some will go on the long list of to be read). I don't see any close connection between consciousness and knowledge, and do not see why an experience must embody knowledge.