 The anti-zombie argument for physicalism. The conceivability argument — which assumes physicalism entails that zombies are impossible — purports to refute it by showing they are possible. As we saw, the simplest version of this argument goes: (1) zombies are conceivable; (2) whatever is conceivable is possible; (3) therefore zombies are possible. However, ‘anti-zombies’ — duplicates of ourselves made conscious by the purely physical facts (Frankish 2007) — also seem conceivable. So we have a parallel argument: (1*) anti-zombies are conceivable; (2) whatever is conceivable is possible; (3*) therefore anti-zombies are possible. But (3) and (3*) cannot both be true, since if the purely physical facts about anti-zombies make them conscious, then the exactly similar physical facts about zombies make them conscious too, and they are not zombies after all (Frankish 2007; Marton 1998; Piccinini 2017; Sturgeon 2000, pp. 114–116). One moral is that we should reject the inference from conceivability to possibility. (Brown 2010 argues that if anti-zombies are conceivable, then zombies are inconceivable.) The most promising reply for exponents of the conceivability argument seems to be to deny that anti-zombies are conceivable (Chalmers 2010, 180).