  The three questions focus respectively on describing the features of consciousness, explaining its underlying basis or cause, and explicating its role or value. The divisions among the three are of course somewhat artificial, and in practice the answers one gives to each will depend in part on what one says about the others. One can not, for example, adequately answer the what question and describe the main features of consciousness without addressing the why issue of its functional role within systems whose operations it affects. Nor could one explain how the relevant sort of consciousness might arise from nonconscious processes unless one had a clear account of just what features had to be caused or realized to count as producing it. Those caveats notwithstanding, the three-way division of questions provides a useful structure for articulating the overall explanatory project and for assessing the adequacy of particular theories or models of consciousness.