The thesis of psychologism which avers that the principles of logic can be justified in psychology remains nebulous, a mere bumper sticker, until we have pinned down what these principles are and what the discipline of psychology is supposed to be. Thus, in his paper "Psychologism Revisited", Thomas Seebohm goes to the heart of the matter by calling attention to the multi- paradigm character of psychology1. If you take psychology to be behavioristic in Skinner's sense, psychologism looks pretty ridiculous. But if you take psychology to include so—called cognitive science, the thesis begins to look more plausible. There are, of course, other ways to understand psychology, but rather than explore the implications for psychologism of various pro- posals about the nature of psychology, I want to begin these reflections by focussing on the consequences of sundry proposals about what to count as the principles of logic.