Consciousness and reductive explanation : has materialism been refuted?

Much of the contemporary literature on consciousness in the philosophy of mind is concerned with how phenomenal experience might be accounted for in scientific theory. One position, due to David Chalmers, Frank Jackson and others, has it that because consciousness is not open to reductive explanation (consciousness is not logically supervenient on the physical), materialism, which is committed to a priori conceptual analysis, must be false. In this thesis, an attempt will be made to discredit this viewpoint. While Ned Block and Robert Stalnaker argue that explicit micro-macro (physical) entailments can only be a posteriori justified, I argue that non-explicit entailments can be handled in the same way, and so can only be empirically grounded. These two arguments taken together suggest that micro-macro entailments cannot be a priori justified. If this is the case, then it would seem that materialism is not committed to a priori conceptual analysis and, thus, the failure of consciousness to be a reductively explainable phenomenon, whether true or not, does not warrant any anti-materialist conclusions. Additionally, in reply to the eliminativist attack, a defense of consciousness and qualia will be mounted