Since the middle 1960's philosophers and historians of science have been concerned with possible relations between philosophy and history of science,¹ and more particularly with answers to three questions: (i) How exactly should history of science be incorporated into the work of the philosopher of science, if at all?² (ii) What weight should be given to historical matters? (iii) To what extent ought history of science be regarded as normative? As these questions were raised and answers formulated, it became apparent that deeper questions needed to be discussed. What are the central tasks of philosophy of science? What is the ontological nature of science? What is the primary concern of a philosopher qua philosopher?³ Many began to argue that philosophy of science, as it had been conceived was not a neutral meta-discipline pursuing pure interests, but rather involved a set of assumptions about the nature of knowledge and the analysis of its structure—assumptions, indeed, which many felt were wrong and should be abandoned.⁴