This paper aims to endorse physicalism over dualism by means of Smart’s concept of identity theory. Smart’s article Sensations and the Brain provides a strong argument for identity theory and accounts for many of it primary objections. Here I plan to first discuss the main arguments for physicalism over dualism, then more specific arguments for identity theory, and finish with further criticisms of identity theory.
Physicalism is the theory that the universe contains nothing other than the physical. Therefore, the universe can be fully explained in physical terms. In terms of the mind, mental states globally supervene on physical states, meaning that there are no changes in the mental without changes in the physical. Identity theory is a type of physicalism, which posits that brain states are identical to mental states. They may not have exactly the same meanings, but the refer to the same thing. This is opposed to Dualism, which contends that mental states are non-physical and therefore different than brain states.
The first main argument for physicalism, and in this case identity theory, is the argument of neural dependence. This argument states that if mental states were distinct from physical states then they would not be affected when the brain is damaged or manipulated. Since scientific research and observation have shown that they are, then it is logical to conclude that mental states are not distinct from physical states.
A dualist may respond with a type of property dualism (epiphenomenalism or interacionism) by saying that mental states supervene on brain states. Therefore, if the brain is damaged, particular mental states will have no supervienence base, and the mind will be affected. This seems to save the dualist perspective but is also extremely limited.
Smart disregards this issue of correlation and claims that mental states and brain states are not correlated, but mental states are brain states. One is not above the other and nothing can be correlated to itself. He simply states that all mental states can be physically explained, and refer to the same thing as brain states, and those that are not at this moment will be as science advances. He calls these “nomological danglers” and says it would be ridiculous to believe that some odd new laws would govern the few things that have yet to be empirically proven when the rest of the world follows the laws of nature. But it can be said that there is no evidence that there is not this psychological set of laws, only that it is highly improbable.
A more substantial counter argument to property dualism not discussed by Smart would be the causal problem. First, Epiphenomenalism claims that mental states have no causal power, which is self undermining because then they would (a) leave no trace (b) have no effect on behavior and therefore there is no reason to believe that they exist.
Second, interactionism claims that mental states do have causal power and behavior is...