 Husserl begins his discussion of psychologism in Part Two with a criticism of what one might call ‘normative anti-psychologism’, that is, the view that psychology and logic are divided by the is-ought distinction (§17). He sides with the proponents of psychologism who maintain that thought as it ought to occur is but a special case of thought as it in fact occurs. Nor is it right, Husserl thinks, to accuse psychologism of circularity; some critics of psychologism had argued that one cannot base normative logic on psychology since psychology itself has some of its foundations in logic. But this misses an important distinction. Psychology can either take the laws of logic as premises and axioms of its own theories, or it can rely on the laws of logic merely as rules of method in accordance with which psychology must proceed. If psychology did the former, psychologism would involve a vicious circle. But psychology presupposes laws of logic only in the second, weaker, sense. And hence psychologism is not based upon a fatal circularity (§19).