Abstract

David Chalmers’ two-dimensional argument against physicalist materialism about consciousness—commonly known as the zombie argument—stands as one of the most extensively debated arguments in contemporary analytic philosophy. One comparatively neglected response to the argument maintains that considerations of conceivability cut both ways: just as the ideal conceivability of phenomenal zombies—entities physically and behaviorally indistinguishable from us yet devoid of phenomenal consciousness—is taken to undermine physicalism, so too the ideal conceivability of exact physical duplicates of ourselves that possess conscious experience (variously called shombies, anti-zombies, or bright illuminati) provides equally compelling grounds for rejecting dualism. In light of the resulting stalemate, proponents of this strategy typically either reject the entailment from ideal conceivability to metaphysical possibility or urge that the debate over the truth of physicalism ought to be “de-prioritized”, since it cannot be resolved on a priori, purely conceptual grounds. In this paper, I argue that the battlefield on which “shombists” aim to challenge “zombists” is less neutral than shombists claim. In fact, the implicit assumptions underpinning Chalmers' original formulation of the zombie argument are inconsistent with at least some versions of physicalism. Specifically, I contend that the conjunction of these assumptions—most notably, the thesis I term phenomenal essentialism, defined as the claim that a subject, by virtue of referring to the way an experience phenomenally appears, is thereby in a position to grasp what that experience essentially is—combined with the ideal inconceivability of zombies (a consequence of the ideal conceivability of shombies, given the conceivability-possibility entailment), yields implications that a physicalist ought to reject. Consequently, physicalists who deem zombies ideally inconceivable are committed to deny phenomenal essentialism and/or other assumptions implicit in Chalmers’ original formulation of the zombie argument. Towards the end of the paper, I suggest that phenomenal essentialism is indeed a highly plausible thesis.