Abstract

A few days after the twentieth anniversary of the death of Karl Popper, and a few days before the fiftieth anniversary of my first meeting with him, my thoughts turn again to his most glorious successes in the epistemology and methodology of science, namely his subtle resolutions of the problems of demarcation and induction. In the eighty years that have elapsed since the presentation of these ideas in the original German text of The Logic of Scientific Discovery countless criticisms, large and small, have been adduced. Several of these criticisms undoubtedly expose defects that need correction, but it seems to me that almost all the black marks awarded are mere minor stains that are easily washed away. This applies especially to all those objections that depend essentially on the thesis that our knowledge, in order to be valid, demands some justification, be it partial and inconclusive. Although I have no hope that I shall be able to open eyes already closed, I plan to examine in this lecture some criticisms, recent and less recent, that have not to date been adequately dealt with. After all, an occasion designed to honour the memory of Karl Popper, and to celebrate his intellectual achievement, provides an opportunity, even an obligation, to expound his beautiful ideas as simply as possible, and to explain why so many of the prevailing criticisms miss their target. Nothing shows that Popper’s ideas are one and all correct, since they are not all correct, but I shall perhaps be able to make it evident that most of them are not mistaken in the respects in which they are commonly supposed to be mistaken.