Abstract
The thesis that anything conceivable is possible plays a central role in philosophical debates about the self. Discussions about free will have focused, at least in the last hundred years, on whether a free yet determined action is conceivable. If it is, and if anything conceivable is possible, then a deterministic physics would by itself pose no obstacle to human freedom. Current debates about the nature and value of personal survival turn on whether it is conceivable for a person to move from one body to another. Discussions about the topic of John Perry’s impressive book, the relation between a person’s mental and physical states, has recently centered on whether it is conceivable for physically identical beings to differ in their conscious experiences. Some claim that zombies, beings physically just like us but without any conscious experiences at all, are conceivable. If they are, and if anything conceivable is possible, then it would seem to follow that facts about conscious experience are not physical. In short, some form of mind-body dualism would have to be right after all.