Abstract

Case 1: Perhaps the phenomenal facts—facts about what it’s like to see red, or to taste freshly made pesto—do not supervene with metaphysical necessity on the physical facts and physical laws. This might be because the connections between the physical and the phenomenal are entirely unprincipled. Alternatively, it might be because whatever psychophysical laws do govern those connections are contingent. Either way, the claim is that there are metaphysically possible worlds that are just like the actual world in terms of what physical laws hold, and in terms of the distribution of physical properties, but which are phenomenally different from the actual world. In some such worlds, different phenomenal facts obtain. In other such worlds, no phenomenal properties are instantiated at all. Call the latter sort of world a ‘phenomenal zombie world’, or, for short, just a ‘zombie world’.