The mind and the body are made up of separate
things, also known as substance dualism - the brain
and the mind interact via the pineal gland
Leibniz proposed a different form of dualism, in
which the mind and the body live separately in
parallel
Dualisms
Property dualisms
Epi-phenomenalism (Huxley)
Argues the physical brain causes mental
states, known as M1 and M2, however, these
mental states have no causal role in changing
our physical states, known as P1 and P2
We respond to stimuli in a reflex like way as
behaviours are caused by muscles contracting
upon receiving neural impulses
Neuropsychology supports this view, arguing that reactions
and functions don't require a conscious awareness.
Behaviourism also supports this view as they made
observations of behaviour without referring to the mind
From an evolutionary standpoint they reject this view, proposing that
if the mind has no causal role, how has it evolved?
Pan-psychism (Nagel)
He argues that there are mental properties in everything
(everything has a mind), and the mind is a non-physical property
of all matter. Mentality is fundamental in the natural world. The
mind can't be reduced to physical states and the mind doesn't
emerge from physical states
Empirically, this can't yet be tested scientifically.
Emergent/ non-reductive materialism (Chalmers)
Argues there are causal relationships between the
body and mind, and all mental states are caused by
a physical state. The mind depends on the body
Everything is considered to be made of physical substances
Physical properties can be described at multiple levels, and higher level properties emerge from lower level ones.
Monisms
Identity theory (Place)
Argued that mental states are identical to physical states.
Mental states can be grouped into types and correlated with
brain states. Brain and mind states are identical
For example, pain is a type of mental state
If brain and mind states are identical, different brain states should produce different
mind states. However, this denies that two different brains (organisms/machines) can
have the same mind states, ruling out AI. (multiple realisability problem)
It also doesnt explain qualia - how we
feel subjectively to be in different mind
states
Neuroscience supports this theory, showing
that many things affect mental and physical
states together, for example, chemicals such as
alcohol also and brain damage
Functionalism (Putnam)
Mental states consist of a set of functional relationships between sensory inputs, other
states, and behavioural output. When these functional relationships are preserved,
mental states are present (multiple realisation)
Invention of
computers and the
Turing machine
Allows the same mental states to arise in different ways (unlike identity theory)
People would argue that if everything has mental states, then the whole
world could be conscious (Block's China brain argument)
Eliminative materialism (Churchland)
Radical claim that our understanding of the mind is completely
wrong and that some/all mental states posited by common sense
don't actually exist and have no role in the mind
Our history of science is full of concepts which have been eliminated e.g. witches -> hysteria. This
reduction should also happen with the mind-body problem. However, it can be argued that subjective
phenomena can't be explained away.
Nagel, 1993
The mind-body problem exists because we want to include the
mental life of conscious organisms in a scientific understanding
of the world. On one hand, everything that happens in the mind
depends on something happening in the brain, or on the other
hand, the subjectivity of mental states cannot be explained by
physical states.
Searle, 1993
Conscious states are caused by lower level
neurobiological processes in the brain