Tuesday, March 07, 2006

(32) Our free will to be cautious in crossing the road

At 11 a.m. on June 18th 1988, I purchased a copy of Bernard Levin’s book In These Times from W H Smiths in Leeds railway station.
It was an impulse buy.

In his introduction, Levin argues for free will against determinism. He points out that those who insist that man’s actions are predetermined still look to see if the traffic is coming before they cross the road.
For this reason he had stopped worrying about free will.

At 6.40 a.m. the next morning I read an interview with physicist Stephen Hawking in The Sunday Times. The interviewer wrote of the Professor’s alarming use of his motorised wheelchair, which, at full throttle, is capable of a decent trotting pace.
Hawking liked to use full throttle and would just shoot out into the middle of busy roads, fearlessly, on the assumption that traffic would stop. His assistants would rush out nervously ahead of him, trying to minimise the danger.

Immediately after telling us of that the interviewer proceeds to the subject of free will vs. determinism. He asks Hawking if his theories are leading us to a modern kind of determinism where the universe is quite preordained and man is to be seen as a mere ineffectual tool of the process.

Hawking replies that determinism would mean that you could predict what will happen, but that, even though we believe that this could be done in principle, in practice we are still a long way from it.

"What about free will?"

"Let’s go back. Free will will take a long time."

They make an abrupt return journey, with, once again, the alarmed aides having to rush ahead to try to stop traffic before it collides with the fearless Professor’s wheelchair.
Hawking reiterated that, in principle, they could predict everything from physics; it is just that the calculations would be too fiendishly complex. Therefore approximations were necessary.

He regarded the idea of free will as a good approximate theory of human behaviour.

"Will it change man to be able to explain everything by a series of equations?" asked the interviewer.
"Does physics therefore have no ethical significance?""Yes. But it takes a great deal to change people. Christianity has been trying for 2000 years."
"So physics is like Christianity?""I think they are rather different: physics doesn’t tell you how to behave to your neighbour."

See also Entry 48.

And in a book published five years later Hawking develops this point still further-
He notes that some people believe that everything is predetermined, yet still look before crossing the road and goes on to explain that there is a completely logical explanation for this which is consistent with the truth of determinism.
I have noticed that even people who claim everything is predetermined and that we can do nothing to change it, look before they cross the road. ... One cannot base one's conduct on the idea that everything is determined, because one does not know what has been determined. Instead, one has to adopt the effective theory that one has free will and that one is responsible for one's actions. This theory is not very good at predicting human behavior, but we adopt it because there is no chance of solving the equations arising from the fundamental laws. There is also a Darwinian reason that we believe in free will: A society in which the individual feels responsible for his or her actions is more likely to work together and survive to spread its values. (pp. 133-135 Black Holes and Baby Universes and Other Essays (1993))

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