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.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.
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.
Much of evolutionary theory is not falsifiable in the true Popperian sense.
7 comments :
Theres a nice talk by Lakatos discussing this very issue that is available online.
http://tinyurl.com/33vvn2
I'm a little confused by the jump from "not falsifying a theory based on a single datum" to "theory unfalsifiable".
While I agree that most theories probably do get patched and edited through time as more facts accumulate, is it true that a theory cannot be falsified? It is not possible for a theory to be completely falsified by a large collection of data, or by another theory?
One of the reasons I quit using "falsifiable" with reference to theories years ago was on account of reading Lakatos. However, I still deem "testable" to be a criterion, in the sense of implying hypotheses that (a) generate fruitful research and (b) make predictions about observations, in particular predictions about what will not be observed under some specified circumstances. Theories put boundaries on observations -- they delimit subsets in the universe of all potential observations, and testing those theories consists in doing research to explore those boundaries and constraints.
(Wilkins, you reading?)
I am glad to see that questions about the falsifiability of theories are beginning to emerge. I think you will find that Popper himself did not believe that theories are absolutely falsifiable.
RG: "...scientists don’t, and shouldn’t, jettison a theory as soon as a disconfirming datum comes in." But Popper agrees, claiming jettisoned theories can be re-tested. They, too, are falsifiable.
LM: "Much of evolutionary theory is not falsifiable in the true Popperian sense." Popper disagreed. See Skeptical Inquirer, September 2004. [excerpt].
Anonymoous
anonymous says,
LM: "Much of evolutionary theory is not falsifiable in the true Popperian sense." Popper disagreed. See Skeptical Inquirer, September 2004.
Popper originally claimed that evolution was not really science. He then changed his mind and claimed that natural selection was testable and falsifiable.
He was right about testing specific predictions of natural selection but it's still true that "Much of evolutionary theory is not falsifiable in the true Popperian sense."
My favorite philosopher of science has long been Feyerabend. When you ignore his notorious shock-the-bourgeois sallies and focus on his core message, that message turns out to be that philosophers have nothing useful to say about how scientists ought to go about their business. Works for me. ;)
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