ABSTRACT
F unctionalism is the doctrine that pain (for example) is identical to a certain functional state, a state definable in terms of its causal relations to inputs, outputs, and other mental states. The functional state with which pain would be identified might be partially character ized in terms of its tendency to be caused by tissue damage, by its tendency to cause the desire to be rid of it, and by its tendency to pro duce action designed to shield the damaged part of the body from what is taken to cause it. 1
Functionalism has been plagued by two “qualia” centered objections: the Inverted Qualia Objection and the Absent Qualia Objection. The Inverted Qualia Objection can be introduced by attention to the familiar inverted spectrum hypothesis, the hypothesis that though you and I have exactly the same functional organization, the sensation that you have when you look at red things is phenomenally the same as the sensation that I have when I look at green things. If this hypothesis is true, then there is a mental state of you that is functionally identi cal2 to a mental state of me, even though the two states are qualitatively
or phenomenally different. So the functional characterizations of mental states fail to capture their “qualitative” aspect. To put the difficulty more boldly, one could define a qualitative state Q as the state someone has just in case he has a sensation with the same quali tative character as my current headache.'1 If inverted qualia are possible, then mental state Q is not. identical with any functional state, and if functionalism claims that every mental state is a functional state, functionalism is false.
