ABSTRACT
Materialism is a thesis regarding what objects, entities, and substances exist; materialism asserts that all objects, entities, and substances are physical. Before the leading materialist mind-body theories can be presented, it is unfortunately necessary to introduce some specialized vocabulary and philosophical distinctions. Many philosophers the days think that there is no problem regarding the nature of mental state tokens and mind tokens. It is accepted by such token materialists that mind tokens are brain tokens and that mental state tokens are brain state tokens. Philosophers have traditionally divided mental states into two basic types: qualitative states, such as perceiving a color or feeling a pain, and propositional attitudes, such as believing that the mind-body problem is interesting or desiring that one's pet parrot should learn to talk. Perhaps the best statement of logical behaviorism is that given by Gilbert Ryle in his book The Concept of Mind.
