40. Consider the main ideas, hypotheses and theories on the topic "Mind & Body"

Mind-Body Identity Theory

Mind-Body Identity Theory is the idea that the mind is just a part of the physical body.

Mind-brain identity theorists like to say that "mental states" are "brain states," but we will see that much more than abstract "states," "events," "properties," and "laws" are involved in explaining how the mind emerges from the brain.

A more extreme position is to simply deny the existence of mind (there is only a brain), or to say that mind is at best an epiphenomenon, with no causal influences on the physical world.

Most identity theorists have been materialists who argued for a form of eliminative materialismor reductionism. Ultimately, they regard physics as the foundational science. They expect that molecules are reducible to atoms, biological cells are reducible to molecules, the brain is reducible to its neurons, and the mind is reducible to the brain.

Other philosophers argue that the mind somehow "emerges" from the brain. They see emergence as producing new "laws" at each hierarchical level of "self-organization." Thus, cells have complex biological laws that emerge from simpler molecular laws. On this view, the mind has "states," "events," "properties," and "laws" that are not predictable based on those of the brain.

Some emergentists believe that the new laws in an upper hierarchical level are not reducible to those of the lower levels. They can thus claim to be materialists or physicalists but deny reductionism. This is known as "non-redcutive physicalism." Other philosophers describe the relationship between hierarchical levels as one of supervenience. They claim that "mental events" supervene on "physical events."

Many writers over the centuries have simply identified the mind with the brain, noticing the empirical fact that when the brain is damaged, mental properties are also impaired. But others, following René Descartes, have assumed that mind is an immaterial, non-physical substance. Descartes and others simply assumed that the mental world could influence the physical world and vice versa, but the mystery of exactly how this might be possible led to the "mind-body problem" the question how two unlike substances, one material, the other immaterial, can interact. Identity theory is one solution to that problem.

The other solution is dualism and a theory of interactionism (notably the work of Karl Popperand John Eccles).

Twentieth-century philosophers best known to argue for an identity of mind (or consciousness) and brain include Ullin T. Place (1956), Herbert Feigl (1958), and J.J.C.Smart (1959).

Place explicitly describes "consciousness as a brain process," specifically as "patterns" of brain activity. He does not trivialize this identity as a succession of individual "mental events and physical events" in some kind of causal chain. He compares this identity to the idea that "lightning is a motion of electrical charges."

("Is Consciousness a Brain Process?", in British Journal of Psychology, 47, pp.44-50 (1956))

Herbert Feigl's work was independent of Place's, but he said that the fundamental idea had been held by many earlier materialist (monist) thinkers.