Philosophical Zombie Argument

A philosophical zombie, or p-zombie, is the subject of a thought experiment in philosophy of mind: a being physically identical to an ordinary human but wholly lacking conscious experience, so that although it would react exactly as a conscious person would if poked with a sharp object, it would feel no pain at all. Proponents of the argument, most notably David Chalmers, hold that because a philosophical zombie is by definition physically identical to a conscious person, even the logical possibility of such a being refutes physicalism, since it shows that conscious experience is a further fact beyond the physical facts. The argument is used to defend the existence of the hard problem of consciousness and has drawn extensive criticism, with some physicalists such as Daniel Dennett arguing that philosophical zombies are logically incoherent and therefore impossible, while others accept their coherence but deny they are metaphysically possible.