The Mind-Body Duality
Source:
Robert H. Wozniak
http://serendip.brynmawr.edu/Mind/Descartes.html
Rene Descartes (1596-1650)
Mind-Body Dualism
Descartes -- The rational mind connects with
the animal body at the pineal gland. Thus,
mind affects body and body affects mind.
Animals have no minds.
 We now know the pineal gland does something
else, but…
 Is there a “mind” or “soul” independent of the
brain?

17th Century Philosophy (1600’s)

Causes and effects must be of similar types:

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Physical cause leads to physical effect.
God is the only true cause – Malebranche
Spinoza’s double aspect theory – mind and
body are both aspects of God in
preestablished coordination.
Leibnitz’s psychophysical parallelism –
causation is rejected, coordination remains.
18th Century Philosophy (1700’s)
All is mind vs. all is body.
 Berkeley’s “Immaterialism” – There is no
body because all matter is perceived by the
mind and can’t be known apart from it.
 Materialism – there is no mind, only matter.
Mental events don’t exist.

La Mettrie, “L’homme machine.”
 States of the soul depend upon states of the body.

19th Century Philosophy (1800’s)
Localization of cerebral function showed that
the brain is the organ of the mind.
 Mental states were shown to affect the body.

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Trauma, mesmeric trance, mental suggestion.
Huxley’s “Epiphenomenalism” –
Mental states have no causal efficacy, like paint on
a stone (neurophysiology is the stone, mind is the
paint).
 We are “conscious automata.”

Interactionism

Carpenter – mind and brain interact:
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Light produces a change in nerves in the brain
that results in mental sensation of seeing.
Desire to move is translated into commands to the
nerves that move muscles in voluntary motion.
There exist circuits between mental and
physical activity.
How this is accomplished is unknown.
Dual-Aspect Monism

Lewes – mental and physical processes are two
aspects of the same psychophysical event.
Mind is subjective while body is objective.
 Terms used to describe the two are not
inter-translatable.


Lewes still provides the best argument for why
psychology cannot be replaced by
neuroscience.
Mind-Stuff Theory
 Higher
properties of mind are
compounded from mental elements
(pieces of mind-stuff).
 When molecules come together at a
level of complexity sufficient to form a
brain and nervous system, correlative
mind-stuff forms consciousness.
James’ Idea of Mind-Stuff
William James
James adopted a pragmatic empirical
parallelism of the sort many psychologists still
support.
 The "simplest psycho-physic formula…” is a
"blank unmediated correspondence, term for
term, of the succession of states of
consciousness with the succession of total
brain processes ..."

 Principles
of Psychology, p. 182
Ongoing Controversy

We still do not know how “mind” emerges
from “body.”

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The nature of the relationship between specific
mental states and the neural substrate is still not
understood.
Those debating mind-body today largely
express ideas that are versions of the
philosophical arguments proposed over the
past 250 years.
Interview with Rodney Brooks
Human as machine, machine as human:
http://www.aaai.org/AITopics/html/show.html
http://news.bbc.co.uk/olmedia/cta/progs/02/hardtalk/brooks19aug.ram