ABSTRACT
I had supposed that the title gave an easy tipoff to my topic, but some puzzled reactions by my Minnesota colleagues show otherwise, which heartens me because it suggests that what I am about to say is not trivial and universally known. The two knights are Sir Karl Raimund Popper (1959, 1962, 1972; Schilpp, 1974) and Sir Ronald Aylmer Fisher (1956, 1966, 1967), whose respective emphases on subjecting scientific theories to grave danger of refutation (that’s Sir Karl) and major reliance on tests of statistical significance (that’s Sir Ronald) are, at least in current practice, not well integrated—perhaps even incompatible. If you have not been accustomed to thinking about this incoherency, and my remarks lead you to do so (whether or not you end up agreeing with me), this article will have served its scholarly function.
