Metaphysics of Pain; Semantics of 'Pain'

Functionalism is often used to identify mental states with physical states. A particularly powerful case is Lewis's analytical functionalism. Kripke's view seriously challenges any such identification. The dispute between Kripke and Lewis's views boils down to whether the term 'pain' is rigid or nonrigid. It is a strong intuition of ours that if it feels like pain it is pain, and vice versa, so that 'pain' should designate, with respect to every possible world, all and only states felt as pain. Hence, in order to settle the dispute, we need to check which of the two - Kripke's use of 'pain' as rigid, or Lewis's use of 'pain' as nonrigid - better meets this intuition. I show that, despite crucial differences in both their semantic and metaphysical assumptions, surprisingly, both views meet this intuition equally well. Thus it appears that this question of rigidity cannot, in principle, be solved, and so, at least with respect to this particular dispute, the jury is still out on whether mental states are identical to physical states.