He just had to make it seem that way, to avoid an early version of Cancel Culture. But we will let philosopher and photographer Laszlo Bencze tell it:
Most of us know that at one point Karl Popper turned his attention to evolution and made the following statement:
“…Darwinism is not a testable scientific theory, but a metaphysical research programme—a possible framework for testable scientific theories.”
— Unended Quest An Intellectual Autobiography, Karl Popper, p. 168
The statement aroused so much controversy and animosity amongst his academic colleagues that he was forced to “recant” in the following statement:
“I have in the past described the theory as ‘almost tautological’, and I have tried to explain how the theory of natural selection could be untestable (as a tautology) and yet of great scientific interest. My solution was that the doctrine of natural selection is a most successful metaphysical research programme. It raises detailed problems in many fields, and it tells us what we would expect of an acceptable solution of these problems.
“I still believe that natural selection works in this way as a research programme. Nevertheless, I have changed my mind about the testability and the logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation. My recantation may, I hope, contribute a little to the understanding of the status of natural selection.”
— Popper Selections, Karl Popper (edited by David Miller), p. 242
Note that his choice of the word “recantation” is significant. He might well have used “reevaluation” or “disavowal” or “repudiation.” I believe he chose recantation deliberately to ally himself with Galileo and to make clear that he was being persecuted by misguided and dimwitted authorities just as Galileo was. Furthermore, he writes that natural selection is “a most successful metaphysical research program.” Wait a minute. Wasn’t that what he was to apologize for? So within his recantation he is reaffirming his original point of view, the very one that got him in trouble.
He goes on to say that he is glad to have an opportunity to make a recantation. Sure he is. He would much prefer to have a root canal without anesthesia than to recant a statement integral to his life’s work as philosopher. Finally, in his summary sentence he is “glad to contribute a little to the understanding of the status of natural selection.” So what did he contribute? He contributed the understanding of natural selection as a metaphysical research program.
I never noticed these points until a friend pointed them out to me. Now they jump forth as obvious.
It’s the price Popper had to pay for being a boffin. Sad.
From Mehmet Elgin and Elliott Sober at History of the Philosophy of Science:
Abstract: Karl Popper argued in 1974 that evolutionary theory contains no testable laws and is therefore a metaphysical research program. Four years later, he said that he had changed his mind. Here we seek to understand Popper’s initial position and his subsequent retraction. We argue, contrary to Popper’s own assessment, that he did not change his mind at all about the substance of his original claim. We also explore how Popper’s views have ramifications for contemporary discussion of the nature of laws and the structure of evolutionary theory.– Popper’s Shifting Appraisal of Evolutionary Theory, Mehmet Elgin and Elliott Sober HOPOS: The Journal of the International Society for the History of Philosophy of Science 2017 7:1, 31-5 (April 15, 2017)
Another friend reminds us of a passage in a book by a journalist who interviewed Popper:
In his autobiography, Karl Popper said he had come to the conclusion that “Darwinism is not a testable scientific theory, but a metaphysical research program.”8 To say that a species now living is adapted to its environment “is almost tautological,” he wrote. “Adaptation or fitness is defined by modern evolutionists as survival value, and can be measured by actual success in survival. There is hardly any possibility of testing a theory as feeble as this.”
Further controversy ensued, for Popper—apparently under pressure in England—partially recanted in 1978. Later, in 1988, I had a chance to interview Popper myself, when he spent a week at the Hoover Institution at Stanford University. I immediately brought up the issue of natural selection. He told me that his opinion had not changed. He also said he thought that natural selection had in fact been falsified “by Darwin’s own theory.” Distortions introduced by sexual selection sometimes meant that offspring were not better adapted than their parents, he said.
When I mentioned that Darwinism had evidently benefited from the idea of Progress, widely accepted in the mid-nineteenth century but widely rejected in the late twentieth, Popper said that “I have been one of the people who have destroyed it.” He said he had “preached” along those lines in his book The Poverty of Historicisms.Tom Bethell, Darwin’s House of Cards (2016) (pp. 14–15)