Monday, August 05, 2019

a brainy argument against determinism (and also materialism)

For some beach reading, I picked up a two-dollar paperback survey of metaphysics by William Hasker, part of the IVP series Contours of Christian Philosophy. My goal was pure curiosity: I wanted to see what topics the author included under this heading. I will probably blog something in dialogue with this book again in the near future. But, for now, it includes an argument against determinism (and, by extension, against materialism) worthy of reproduction against future forgetting. From pages 47-48, italics rendered as in the text:

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"It is clear . . . that rational thinking must be guided by rational insight in the light or principles of sound reasoning. That is to say, one must "see," rationally, that the conclusion is justified by the evidence--and one is helped to see this by principles of reasoning, such as the laws of inductive and deductive logic and the like. Furthermore, and this point is crucial, one accepts the conclusion because one recognizes that it is justified by the evidence. It is this recognition which brings about the acceptance.

"Now let us suppose that all human thinking is physically determined in the following sense: (1) Every thought or belief accepted by a person is a result of that person's brain being in a corresponding state. (2) We assume, provisionally, that the physical indeterminacy which exists at the quantum level makes no perceptible difference in the overall functioning of the brain. So that (3) every brain state, and therefore every thought and belief of the person, is fully determined by the physical functioning of the brain in accordance with the deterministic laws of physics.

"Is it not evident, on this supposition, that rational thinking is an impossibility? It cannot be true, on this assumption, that anyone's thinking is guided by rational insight; rather, it is guided entirely by the physical laws which govern the brain's functioning, which proceed with no regard to whether the thought processes they generate correspond to principles of sound reasoning. Occasionally, to be sure, it may happen that the thought processes generated by the physically determined functioning of the brain will arrive at a conclusion which is correct. But this, when it happens, is simply a fortunate accident--and to say that a conclusion is reached by accident is incompatible with the claim that that conclusion was reached by rational thinking .Therefore, if all human thought is physically determined, then no one ever thinks rationally.

"Nor is the situation changed if we modify our assumptions (and our definitions of "physically determined") so as to allow that sometimes random, physically undetermined events within the brain have a perceptible effect, so that a different conclusion is reached than would have been the case without the random event. For such a random event is no more responsible to rational insight than was the physically determined brain process of the previous model. What is needed for rationality is not simply an injection of randomness into the physically deterministic brain functioning, but rather an infusion of rational insight as a factor which guides and directs the thought processes. But to accept this is to give up physical determinism altogether. And so our conclusion: If physical determinism is true, no one ever thinks rationally."

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The summary of the above is simply this: that a car, acting according to its own structure, cannot take you where you want to go. Even should it, somehow and by your good fortune, deliver you safely to a desired address, the result says nothing about the cause. Rational insight, one's reason, and in this metaphor the driver, must come from elsewhere.

What this means for emergence, I'm not wholly sure. Emergence theorist assert that the driver emerges from the complex and perhaps ineffable workings of the machinery, subject as it is to physical laws. If that is the case, doesn't this but shift the problem? In that case, the emergent property becomes our metaphorical car, and we are left asking how it knows where to go.

Some time ago, I wrote a post akin to this one called "Plantinga Pulls a Sampson." In it, Alvin Plantinga invokes natural selection, whereas William Hasker, who wrote the above, was addressing the debate between free will and determinism.

As I consider both posts, I can begin to see my own outline. I see a skepticism of reductive materialism, scientism, and "nothing but" physics--no surprise there. What is embraced is more interesting: a qualified dualism:

  • the mind as not the same as the brain but connected, perhaps as an emergent property
  • the self as a (qualified) free agent [not theologically free, but naturally so]
  • a humanity that, though subject to material laws, transcends them
  • reason/ethical judgment, the derivation of which could be the community or someplace altogether mysterious in origin

Note: this post does not well address the point of the quotation itself which is epistemology, which is about determining what is true.

1 comment:

  1. Note the way that theologian Roger Olson uses determinism in his discussion of evil:

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    I would find it impossible to believe that the European Holocaust, for example, was explainable in scientific terms. Even the historian cannot fully explain it. They can explain conditions that influenced it (such as the Versailles Treaty), but they cannot explain what made it “evil.” If they could describe and explain it exhaustively in scientific and socio-historical terms it would be deterministic and if something is determined it cannot be called evil. Evil is irreducible. When it is reduced it loses its evilness.

    Evil points to something spiritual and transcendent. A transcendent standard of goodness and a spiritual nature of humanity, mind and will that cannot be reduced to chemistry. Once it is reduced to chemistry, either biological or social, it loses its evilness and becomes something less than evil.

    If I believed that “evil” can be explained by science alone, I would stop believing in evil. The word and the concept require something beyond the ken of science.

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