Abstract

Over the course of many years, as a teacher, scholar, and friend, Ruth Zimmerling has impressed on me the importance of precisely defining one’s concepts. After all, if there is no agreement on the intension and extension of a concept, it is impossible “to assess the truth or falsity or, more generally, the correctness or incorrectness, of propositions, hypotheses or theories”. The statement is almost self-evident: Without precisely defined concepts, the whole endeavour of science becomes pointless, and scholarly discourses are bound to turn into dialogues of the deaf.