Zadok Paper S100 Winter 1999
The Nature of Humans-Mind and Brain; Body, Soul and Spirit
by Alan Gijspers

The problem of determinism

One of the main problems with a classic reductionistic approach to the mind-brain issue is the view that if the biological is caused by the physical then I am simply the product of biochemical reactions which are entirely determined. My free will is thus a myth and I am simply a product of my genes. This is a very mechanistic view of humans but it certainly is the dominant view of the late 19th and early 20th century. It is so pervasive that we do not realise all the hidden assumptions within this world view, nor that this approach is actually a metaphysical rather than a scientific statement.
A mechanistic view of behaviour is sometimes refuted by pointing to the indeterminacy of basic particle physics. The argument goes something like this: if we cannot fully predict particle behaviour then the rest of our behaviour must also be unpredictable. However, this does not follow, for statistics show that while individual events (like the toss of a coin) may be unpredictable, the sum of events (like the fact that over time heads and tails will come out equally) will be remarkably accurate. This of course ensures the financial viability of most casinos. We do not know who will win, but we know someone will win, most will lose and the owners will get the profits. Thus micromolecular unpredictability does not guarantee macromolecular unpredictability.

Can chaos theory help refute determinism? Polkinghorne attempt to create "open ends" from chaos theory so that there is an openness to top-down causality.70 However, chaos theory is a physical theory which states that tiny alterations in initial conditions will have a marked effect on the outcome of a 'chaotic' system. Here systems are unpredictable because we cannot define all the initial conditions. But that does not mean that chaos systems are indeterminate. Whatever perturbations in the initial conditions, the system has a determined (though unpredictable) outcome. Hence, chaos theory does not create room for input from 'spiritual sources' or top-down causality to influence the outcome of chaotic systems. As far as I can see, chaos theory describes unpredictability rather than indeterminacy. Chaos theory still espouses determinism.

Donald MacKay, a Christian neuroscientist, makes much of the incompatibility of objective (third person) accounts on a person's behaviour with subjective (first person's) accounts of that same behaviour. "Thus you and I, even if our brains were as mechanical as clockwork, would be mistaken to believe that there exists, unknown to us, any complete prediction of a choice we have not yet made, which we would be correct to accept as inevitable if only we knew it. In this sense your future, in at least some details, is logically indeterminate."71

Polkinghorne finds a number of dubious points in this description. How could an external investigator know everything to make a prediction without grossly interfering with the brain? Second, self-referrant operations are notoriously tricky. He further argues that the complexities of the mind are self referrant at multiple levels.72 His refutation of determinism in the end is a philosophical one: if we believe in determinism we destroy rationality, for the argument put forward would not be a reasoned argument but the mouthing of an automaton.73 I believe we cannot operate as if we are determined. It would make every thing we do and any sense of personal responsibility meaningless. We cannot function as human beings this way. This does not mean that we have unlimited freedom, but we do exercise some.

To: Appropriate models of mind function

Alan J. Gijsbers MBBS FRACP DTM&H PGDip Epi, is Specialist Physician at Turning Point Drug and Alcohol Centre and at the Department of Drug and Alcohol Studies St Vincent's Hospital. He is a Visiting Physician at the Epworth Hospital, a Senior Lecturer in Clinical Medicine at the Department of Psychological Medicine Monash University and Senior Fellow at St Vincent's Hospital Clinical School, University of Melbourne. He also contributes to a Dual Diagnosis Clinic at the St John of God and St Vincent's Collaborating Centre consulting on people with both Drug and Alcohol and Psychiatric Disorders. He is a fellow ISCAST and editor of their national bulletin. He also somehow manages to be a husband to his wife, Lois, and a father to three children.