The Structure of Scientific Revolutions
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JC pontificates about technology
An occasional series.
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The Structure of Scientific Revolutions, by Thomas Kuhn
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Small and perfectly formed: one of the greats of 20th Century Philosophy
A true classic of Twentieth Century literature, this wonderful little book, which argues for the contingency of scientific knowledge, deserves space on the bookshelf next to The Wealth of Nations (identifying the contingency of economic wellbeing and value), Hume’s A Treatise of Human Nature (causal scepticism), The Origin of Species (the contingency of biological development) and Contingency, Irony and Solidarity (the contingency of language) - along with those perennially confusing continental stalwarts Friedrich Nietzsche and Ludwig Wittgenstein, as representing the fundamental underpinnings of modern Relativist thought.
Thanks to the Chomskies, Dawkinses and Sokals of this world, who have cunningly bound perfectly sensible Cognitive and Ethical Relativism to silly Post-Structuralism, proper Relativism has become a dirty word these days.
It may be unfashionable but it’s also powerful, and if you want to understand it, and its power, The Structure of Scientific Revolutions - as short and beautifully written a classic of philosophy as you could possibly ask for - is as good a place as any to start.
Following publication of “Structure”, Kuhn had a famous public debate with Karl Popper over what counts as science and the way in which science develops over time. Popper had, in The Logic of Scientific Discovery, made the invaluable observation that “verification” as a standard for science is too high, since as a matter of logic an argument based on induction (“since the sun has risen on every day in recorded history, therefore it will rise tomorrow”) can never be proven true: for all our folksy expectations, current cosmology predicts that there will be a point in the distant future when the sun will explode, and therefore will not rise tomorrow.
In lieu of verification as the scientific gold standard, Popper asserted (seemingly plausibly) that valid scientific theory could be assessed by the lack of any falsifying evidence among the data. To be of any use, a scientific theory must be “falsifiable”: it must narrow down from the list of all possible outcomes a set of predicted ones, and rule the rest out. Theories which cannot be falsified by any conceivable evidence don’t do that, so fail at science’s fundamental task. They are not science.
Thomas Kuhn’s insight was to offer the historian’s perspective that, while that might be theory, that’s not what science has ever done in practice. Scientific theories are never thrown out the moment contradictory evidence is observed: the dial is tapped, the experiment re-run, and “numerous articulations and ad hoc modifications of their theory” are devised to eliminate apparent conflict. When the data won’t do what they’re meant to, sometimes it is the question which is rejected as being irrelevant, and not the answer predicted by the theory.
All this activity takes place inside what Kuhn describes as a “paradigm” - a “particular coherent tradition of scientific research". The paradigm governs not only the theory but the education, instrumentation, rules and standards of scientific practice, and is the basis on which the scientific community decides which kinds of questions are and are not relevant to the development of scientific research. A paradigm claims exclusivity over the adjudication of its own subject matter, and one only has authority to pronounce on a scientific problem once one has been fully inducted: evolutionary biologists will not take seriously the biological assertions of fundamentalist Christians, for example. Fundamentalist Christians who take biology exams will fail, and thereby will never be able to authoritatively comment on biological matters.
Paradigms are useful for the jobbing scientist: they provide a pre-agreed framework — what Daniel Dennett would call a “crane” — on which additional scientific research can be undertaken without having, literally, to re-invent the wheel. Kuhn characterises this sort of “normal scientist” as being involved in “puzzle solving” in exactly the sense that one solves a crossword puzzle. You have a framework of rules for how to solve the puzzle; you have problems (the blank spaces on the puzzle) and you empirically obtained evidence (clues) which you manipulate using the rules to produce predictions (or answers), and each newly discovered answer then acts as an additional clue to solve the remaining problems.
Superficially, this all sounds fine, but there are jagged corals just below the surface: Once inside a paradigm it informs your view of the world so thoroughly you cannot conduct research outside it. To solve a crossword puzzle, you must first have *some* pre-determined rules of engagement (the same puzzle can be solved, differently, with different sets of rules: a “cryptic” crossword yields different answers for the same boxes, and perhaps even the same clues, to a “quick” crossword. But to solve it one needs to use one or the other). Unlike a crossword, Mother Nature doesn’t come with a label saying “cryptic” or “quick". So how do we know which paradigm to use? Can we judge the truth or falsity of the paradigm, other than in terms of the paradigm itself?
Kuhn says no. This is an immensely powerful idea. Not only does it undermine the certitude many people have about their own ways of life, it seems to opens the door to all the wacky alternatives, with no objective means of choosing between them. So, can we really not choose between radiotherapy and healing crystals?
That this might be the case terrifies a lot of people, especially scientists, and Kuhn gets a lot of the blame for this state of unease. Post-Modernism: It’s all Kuhn’s fault.
But this is surely to shoot the messenger: Kuhn’s great contribution is not to say that healing crystals are in (he does not) but to say that the sacred and immutable link between science and truth is out, and we owe it to ourselves to keep an open mind about whatever we believe. After all, the history of science (which is what Kuhn started out writing about) is a long history of frequent revolution. Either all the theories scientists have ever believed up to the current day are wrong, always were, never really counted as science and we’re just lucky to be around when the human race has finally got it right — wishful thinking — or the revolutionary history of science, which no-one disputes, tends to back up what Kuhn is saying.
Science does evolve, through the great algorithm of human discourse, and the dominating theories through time will tend to be the ones which most of us are persuaded work the best for us (whether we’re right or not is really beside the point). What persuades in Tehran may differ from what persuades in Texas. All Thomas Kuhn cautions against is either side taking its own position as a given.
His enterprise is therefore fundamentally democratic, placing epistemological legitimacy in the hands of the entire community, as contingent and random as it may be from time to time, and not a self-selecting, self perpetuating elite.
One thing economic theory tells us is that concentrating economic control in a small part of the population (as in a monopoly) generally works out worse for everyone except the monopolist. There’s no reason to suppose that concentrating intellectual authority should be any different.
In the Western Hemisphere — outside the Grateful Dead tour circuit, at any rate — intellectual authority mostly resides with established science, but it has to work — literally — to earn our respect.
Richard Dawkins may not like that sort of accountability but, not being a scientist, I do.