Explain how the threat of property dualism arises from the identity theory, and present Smart’s response to it.

What is the mind-brain identity theory? Explain how advocates of this theory (Place, Smart) appeal to the claim that the identity of mental and brain states is contingent in defending it against objections. Explain how the threat of property dualism arises from the identity theory, and present Smart’s response to it. Then present Kripke’s attack on the strategy of defending the identity theory by claiming the identity is contingent. Be sure to discuss the roles played in this attack by the notion of a rigid designator and by the distinction Kripke draws between necessity and a prioricity.