Karl Popper on Creationism

“The theory of natural selection may be so formulated that it is far from tautological. In this case it is not only testable, but it turns out to be not strictly universally true.”

“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 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 most offspring leave 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.”