Changing Your Mind: Are Scientific Theories Falsifiable?

 
Rebecca Goldstein is a philosopher at Havard University (USA). She used to think that Karl Popper's view of how science is done was correct. Now she's changed her mind ... [Falsifiability]

Said Popper: The criterion of the scientific status of a theory is its falsifiability.

For most scientists, this is all they need to know about the philosophy of science. It was bracing to come upon such a clear and precise criterion for identifying scientific theories. And it was gratifying to see how Popper used it to discredit the claims that psychoanalysis and Marxism are scientific theories. It had long seemed to me that the falsifiability test was basically right and enormously useful.

But then I started to read Popper’s work carefully, to teach him in my philosophy of science classes, and to look to scientific practice to see whether his theory survives the test of falsifiability (at least as a description of how successful science gets done). And I’ve changed my mind.

....

...scientists don’t, and shouldn’t, jettison a theory as soon as a disconfirming datum comes in. As Francis Crick once said, “Any theory that can account for all of the facts is wrong, because some of the facts are always wrong.” Scientists rightly question a datum that appears to falsify an elegant and well-supported theory, and they rightly add assumptions and qualifications and complications to a theory as they learn more about the world. As Imre Lakatos, a less-cited (but more subtle) philosopher of science points out, all scientific theories are unfalsifiable. The ones we take seriously are those that lead to “progressive” research programs, where a small change accommodates a large swath of past and future data. And the ones we abandon are those that lead to “degenerate” ones, where the theory gets patched and re-patched at the same rate as new facts come in.

Many people agree with Rebecca Goldstein but I still hear from lots of Popperians. It's very annoying to see my fellow scientists attack Intelligent Design Creationism on the grounds that it doesn't conform to Popper's idea of science—it's not falsifiable. That's true but irrelevant. Much of the best kinds of science also don't conform to Popper's ideas.

Much of evolutionary theory is not falsifiable in the true Popperian sense.

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