Abstract

Zombies are unconscious objects with conscious physical micro-duplicates. If zombies are possible then physicalism is false. It has been argued that zombies are possible if conceivable for an agent with ideal rationality. At any rate, they are possible only if so conceivable. This essay uses a mereological constraint to highlight the fine-grained differences between actually conscious physical objects and certain of their actually consciousness-incapable proper parts. These mereological considerations form the basis of an argument by dilemma that zombies are inconceivable. Either an arbitrary actually conscious object might have had simpler consciousness-capable parts than it in fact has, or not. The affirmative horn leads to a version of panpsychism that is inconsistent with the ideal conceivability of zombies. The negative horn rules out zombies as incoherent. The upshot is a new reason to deny the conceivability of zombies.