We have completed out survey of the most important trends in philosophy in science, prompted by an interest that is not only historical.¹ In philosophy, more than in other spheres of knowledge, the present state of research is conditioned by the fact that others have already addressed a given topic. It is no accident that philosophical treatises are overloaded with references to the literature. The main goal of this survey was to "draw lessons from history," and to follow those lines of thought which, even today, in a climate so vigorously regulated by the natural sciences, would have a chance of becoming philosophical ideas about nature. It is time to put our conclusions in order.