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Wednesday, September 22, 2010

Scientific truth and the emotion of belief

by John MacBeath Watkins

I've been delving into Thomas Kuhn's The Structure of Scientific Revolutions, a book with a great reputation among lefty intellectuals in the humanities.  The first thing that strikes me about it is that it's not much use to someone trying to do science.

Kuhn applies the concept of structuralism to scientific knowledge and analyzes the history of science in what looks to me like dialectical idealism, Hegel's concept of how history progresses.  Structuralism, in political theory, has been the province of new-Marxists, and Marx used Hegel's concept of the dialectic while changing it to dialectical materialism, analyzing history in terms of more concrete conflicts.

So it's no surprise that Marxists have used Kuhn's work to argue that science's claim to be about objective truth is a load of hooey, that it's really shaped by history and power.  I would find this more persuasive if power had a better record of shaping science.  Despite the efforts of the Catholic Church, science still thinks the earth revolves around the sun; despite the efforts of Stalin and the Soviet authorities, Trofim Denisovich Lysenko's Lamarkian theories about the heritability of acquired traits did not hold sway even in Soviet biological science for long.  It just didn't produce results.

Kuhn's main competition for the interpretation of science is Karl Popper, who argued that scientific truth can only be arrived at through falsifiability.  That is, you have to be able to check the statement against observations, and for it to be a scientific truth, it must be possible to prove it false.  Except, of course, the statement that scientific truth must be arrived at through falsifiability, that you have to accept on his logic, which means that his theory about how to arrive at scientific truth is not itself a scientific truth.

Popper's theory has the virtue of resembling the way science is actually done, although nobody has yet found a way to test string theory (which makes some scientists question whether string theory is science at all.)  One problem with this theory is that it would not recognize some scientific revolutions.  Popper thought the theory of natural selection was untestable, "a most successful metaphysical research programme," although it strikes me that the theory is easily testable with a few Petri dishes of bacteria and some antibiotics.

He counted the search for truth as among the strongest motivations for the advancement of science.  Truth is one of the more slippery concepts in philosophy, though.  He thought true statements are statements that correspond to observable facts, a statement that seems at once obvious and at odds with the emotional nature of the response most of us have to the question of whether things are true.  If it were that simple, would people get so excited about whether things are true?

My own view is that truth is a word we use to describe that which we believe without question.  Belief is an emotion akin to love, which is why Truth and Beauty are so often mentioned together.  The question, therefore, is how we should form our beliefs?  Different cultures at different times have used different methods.  As we discussed here, many people when faced with facts that contradict their beliefs experience backfire, that is, they end up holding their false belief more strongly in reaction to what they perceive as an attack on them.  If you view belief as an emotion, this is understandable.  It's as if you told them their lover was ugly, and they responded by saying "take that back!"

The subversive thing about science is that it attempts to hold a dialogue without backfire, a dialogue in which facts trump preferences.  Whereas religion offers the comfort of eternal verities, scientific truth is conditional; it is only true so long as a better explanation does not appear.  Those who prefer the stability of an eternal truth react strongly against this notion of truth.

In The Laws, Plato suggested a society based upon certain truths.  Those who questioned those truths would be brought before the Nocturnal Council, which would attempt to persuade them they were wrong.  If they could not persuade them, they would be required not to speak of their doubts about the truths on which their society was founded.  If they insisted on spreading their doubts, they would be killed.  Thus, the stability of society is preserved.

This seems almost like a parody of the way political and religious truth operates.  Through most of history, rulers have relied upon force and faith for their legitimacy.  The modern form of liberal democracy owes its start to the Enlightenment, with its preoccupation with rational exploration of the truth, as does the modern form of science.

We now seem to be experiencing a sort of counter-Enlightenment, in which everything from fundamentalist religion, New Age beliefs and conservative and Marxist critiques of science, point away from the legitimacy of reason as a way to arrive at truth.  There is even an element of cross-pollination.  Philip Johnson, a retired law professor who has become a prominent figure pushing creationism as more legitimate than evolution, quotes Kuhn in an effort to show that science requires all evidence to fit the dominant paradigm, no matter how wild the contortions, unless another paradigm comes along to replace it.  This seems to me to be a strange interpretation of how science works.  Many things are regarded as unknown, with competing hypotheses attempting to explain the unknown and giving scientists a framework for experiment.  Disproving an orthodox belief and coming up with a better explanation has been the foundation of many a scientific reputation.  As for paradigm shift, when the existing paradigm does not adequately explain the data, those competing hypotheses are the possible new paradigms.  Kuhn maintained that a new paradigm was incommensurable with the old one, that is, it could not be proved by the methods of the old one.

It strikes me a more parsimonious explanation would be that science relies on the integrity of the dialogue for proof of a hypothesis.  First, you think about what the world would be like if the hypothesis were true, then you look at the world and see if it's like that.  Holders of the old paradigm accept or reject the new hypothesis based on the legitimacy of the observations and how well they fit the hypothesis, without backfire -- that is, without the emotional response that you will continue to believe what you wish regardless of the facts.  This is why it's a big deal when scientists cheat, as they sometimes do.  All lies are parasitic on legitimate communication, relying for achieving their ends on the assumption that the speaker is telling the truth.  A lie is the cowbird of declarative sentences, undermining the survival of truth.  Fabricating experimental results is a form of lie, and is particularly destructive because the listener is not protected by the usual reaction of backfire; the listener's part in the dialogue is to be open to persuasion by facts.   The integrity of the dialogue relies on the speaker be providing factually accurate evidence and the listener being willing to change a belief based on evidence.

Why does it not surprise me that a law professor would combat science by instilling doubt that this is how science works?  After all, instilling doubt about science has long been a tactic used by tobacco company lawyers, and the technique of instilling doubt has been exported to other industries.  Casuistry, thy name is lawyer.

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