D. Gene Witmer

Charles Siewert has given us an ingenious thought experiment involving a limited lack of conscious experience. The possibility of the described case is incompatible with a number of popular theories of consciousness. Siewert acknowledges, however, that this possibility is not a direct threat to "hidden feature" theories. I aim to do two things: first, strengthen his defense of the claim that the case is genuinely possible by considering and rejecting some further attempts to explain away our temptation to believe it possible; and second, to explore how a hidden feature approach could be developed and made plausible

The manifestability argument presented by Papineau and Loewer turns on the premise that nonphysical properties are capable of making a difference to physical conditions. From this and the completeness of physics a strenuous supervenience conclusion is supposed to follow. I argue that the plausible version of this premise implies a weaker supervenience thesis only, one that is too weak to be of any use for a physicalist. There is a more contentious premise one might use to deduce the needed conclusion, but that more contentious premise has no empirical support