States that sensations are brain processes in the sense of identity: they are the same thing. Brain processes dont cause sensations, they are sensations. Opposes Dualism.
In Sensations and Brain Processes, Smart uses Occam’s razor to argue that a purely physical identity theory of mind is superior to dualism because it avoids unnecessary non-physical nomological danglers (something that cannot be explained by or integrated into established scientific laws) and reduces the types of entities in the universe.
- Mental states causally affect the physical world.
- Pain causes withdrawal. Beliefs cause speech. Desires cause action.
- The physical world appears causally closed.
- Physical events already have physical causes. Your arm moves because neurons fire, muscles contract, chemical signals propagate, etc.
- So mental states must be physical states.
- If the mental is not identical to the physical, there is a problem. Either mental states are extra nonphysical causes, which threatens physical science, or they are causally irrelevant decorations.
- The best candidates are brain states.
- Therefore mental states are identical to brain states.
Type identity vs Token identity
todo