Central-state materialism ( = CSM) is a very strong, but also very exciting theory of mind according to which each mental state is identical with a state of the central nervous system. CSM thus goes considerably beyond early versions of the identity theory of mind, since those early accounts (e.g., those of Place and Smart) held only that sensations are to be identified with neural events. CSM, by contrast, is a thesis about all mental states; every mental state is held to be a state of the central nervous system. In fact, as we will see shortly, CSM is an even more sweeping thesis than this formulation of it suggests, since it is not concerned simply with mental states.
One prominent defender of CSM, David Armstrong, has maintained that CSM can be established by means of a two-step argument.