Identity Theory and the Mind as Brain States

The mind-brain identity theory emerged in the 1950s as a physicalist alternative to both Cartesian dualism and behaviorism, proposed independently and near-simultaneously by U.T. Place, in "Is Consciousness a Brain Process?" (British Journal of Psychology, 1956), and J.J.C. Smart, in "Sensations and Brain Processes" (Philosophical Review, 1959). Rather than analyzing mental terms as being, by definition, about behavior, as Ryle had done, the identity theorists proposed that mental states such as pain or visual sensation are, as a matter of contingent empirical fact discovered by science rather than established by conceptual analysis, literally identical to particular states or processes of the brain and central nervous system. Smart's favored example was the sensation of pain, which he took to be identical to the firing of C-fibers (a class of nerve fibers associated with pain transmission), so that "I am in pain" and "My C-fibers are firing" would, if the identity theory is correct, both be reports of one and the same physical event, described in two different vocabularies — an everyday, phenomenal vocabulary and a technical, neurophysiological one.