On Mad Pain and Martian Pain: My Experienced Pain is Concrete — Even more trouble with Functionalism

David Lewis (1980) talks about two sorts of non-standard pain. Mad pain has a type-identity relationship with normal pain without the normal human behavioural (functional) outputs. Martian pain has a functional relationship with normal human behaviour, but is implemented differently. By trying to account for these different situations, both of which we want to call pain, he tries to define pain as something which happens to normal members of a natural kind.