The Mind-Body DualitySource: Robert H. Wozniakhttp://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:

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.

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:

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.” 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 BrooksHuman as machine, machine as human:

http://www.aaai.org/AITopics/html/show.htmlhttp://news.bbc.co.uk/olmedia/cta/progs/02/hardtalk/brooks19aug.ram