These are excerpts and elaborations from my book "The Nature of Consciousness"
The Age Of Materialism As the mind-body problem
became the "mind-brain problem" during the course of the 20th
century, materialism begot "physicalism", according to which a mental
state "is" a physical state of the brain. Note that the emphasis on
the brain is not completely natural: I feel pain in my foot, not in my brain.
But progress in neurophysiology has created a fascination with the brain, which
some people describe as the most complex thing in the universe. Therefore the
emphasis shifted from the body to the brain although there really is no
evidence to rule out that the rest of the body does not affect the mind (there
is evidence to the contrary). The “identity theory“ (the
one pioneered by Feigl) states, point blank, that
mental states "are" physical states of the brain (just like lightning
is "identical" to a stream of electrons). Since it is a little
implausible to assume that for every single mental state there is a unique
neural state, a variant of identity theory relaxed this constraint: the “token
identity theory“ (Donald Davidson) does assume that any mental state is identical to a physical state,
but the physical state corresponding to a given mental state is not necessarily
always the same one (this allows for two people to have the same feeling, or
for the same person to have the same feeling twice, without having every single
neuron in the same state both times). The most difficult problem
for materialism is to explain how the mind, and especially feelings, can arise
from material processes: how can electrochemical activities in my brain
suddenly turn into the feeling of pain or fear? John Searle has summarized the problem as a
paradox: either the identity theory leaves out the mind, in which case it is
implausible, or it does not, in which case it is not materialist anymore. Back to the beginning of the chapter "Mind and Matter" | Back to the index of all chapters |