if we can find even one psychological predicate which can clearly be applied to both a mammal and an octopus (say, "hungry"), but whose physical-chemical "correlate" is different in the two cases, the brain state theory has collapsed. It seems to me overwhelmingly probable that we can do this (Mind, Language, Reality, p. 436).But can we? What reason is there to believe that an octopus, say, is hungry like us or feels pain like us? It seems that we have to resort to analogical arguments in this case. For example:
- When human beings eat, it usually means that they feel hungry.
- Like human beings, octopuses also eat.
- (Therefore) Like human beings, when octopuses eat, it usually means that they feel hungry.
- When a person's finger is pricked with a needle, s/he withdraws his/her finger because s/he feels pain.
- Like humans, when a chimpanzee's finger is pricked with a needle, it withdraws its finger.
- (Therefore) Like humans, when a chimpanzee's finger it pricked with a needle, it withdraws its finger because it feels pain.