by Eric Schwitzgebel
According to a broad class of materialist views, conscious experiences — such as the experience of pain — do not supervene on the local physical state of the being who is having those conscious experiences. Rather, they depend in part on the past evolutionary or learning history of the organism (Fred Dretske) or on what is “normal” for members of its group (David Lewis). These dependencies are not just causal but metaphysical: The very same (locally defined) brain state might be experienced as pain by one organism as as non-pain by another organism, in virtue of differences in the organisms’ past history or group membership, even if the two organisms are molecule-for-molecule identical at the moment in question.
Donald Davidson’s Swampman example is typically used to make this point vivid: You visit a swamp. Lightning strikes, killing you. Simultaneously, through incredibly-low-odds freak quantum chance, a being who is molecule-for-molecule identical to you emerges from the swamp. Does this randomly-congealed Swampman, who lacks any learning history or evolutionary history, experience pain when it stubs its toe? Many people seem to have the hunch or intuition, that yes, it would; but any externalist who thinks that consciousness requires a history will have to say no. Dretske makes clear in his 1995 book that he is quite willing to accept this consequence. Swampman feels no pain.
But Swampman cases are only the start of it!
