Hard problem of consciousness

The term hard problem of consciousness was coined by David Chalmers at a conference in Tucson, when he distinguished between "easy problems" of understanding consciousness (such as explaining the ability to discriminate, integrate information, report mental states, focus attention, etc.) and contrasted them with the "hard problem".

Various formulations of the "hard problem":
 * "Why does awareness of sensory information exist at all?"
 * "Why do qualia exist?"
 * "Why is there a subjective component to experience?"
 * "Why aren't we philosophical zombies?"