Karl Popper argued long ago that Darwin’s theory of evolution was never a matter of science; it was always about faith.
Hmmmm. It's been a long time since I read Popper, but I dug a bit into Philosophy of Science when I was studying philosophy as an undergrad, and Philosophy of Science would likely have been my area of specialty had I gone to grad school in philosophy. I read enough of Karl Popper's work to have at least some sense for what he was about, and this quote struck me as questionable. So I did a bit of digging.
I did a Google search on the terms "Karl Popper Darwin", and the first item returned in that search was this bit of Creationist literature that includes this bit:
"Darwinism is not a testable scientific theory," Popper says, `but a metaphysical research programme."
Well, that certainly seems damning, although the article here seems more interested in the fact that Darwin and Popper were both Englishmen, as though it should be an inconvenience to evolution that someone from Darwin's own country didn't agree with Darwin's theory. The article makes no effort whatsoever to dig into why Popper might have said what he said; it just plops that bit about Englishmen out there.
But anyway, if that's the sole bit of Creationist reliance on Popper to deny the scientific nature of evolution, well, they're not on very strong footing. To return to the Google search above, the seventh Google result produces this:
The fact that the theory of natural selection is difficult to test has led some people, anti-Darwinists and even some great Darwinists, to claim that it is a tautology. A tautology like "All tables are tables" is not, of course, testable; nor has it any explanatory power. It is therefore most surprising to hear that some of the greatest contemporary Darwinists themselves formulate the theory in such a way that it amounts to the tautology that those organisms that leave the most offspring leave the most offspring. And C.H. Waddington even says somewhere (and he defends this view in other places) that "Natural selection ... turns out ... to be a tautology". However, he attributes at the same place to the theory an "enormous power ... of explanation". Since the explanatory power of a tautology is obviously zero, something must be wrong here.
Yet similar passages can be found in the works of such great Darwinists as Ronald Fisher, J.B.S. Haldane, and George Gaylord Simpson; and others.
I mention this problem because I too belong among the culprits. Influenced by what these authorities say, 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 is 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 this way as a research programme. Nevertheless, I have changed my mind about the testability and 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.
So: apparently the Creationists who are attempting to draft Sir Karl Popper into their cause don't know what they're talking about. Imagine that.