While the use of so-called idealizations in science has been widely recognized for many years, the philosophical problems that arise from this use have received relatively little attention. Even a cursory reading of the philosophical literature devoted to these problems reveals that the following questions remain unanswered: In general, what, if any, are the distinguishing characteristics of idealizations? More specifically, do idealizations have any distinguishing syntactic or semantic characteristics? In addition to these questions there exist the following pragmatic questions, questions (...) relating to the ways in which idealizations are used in science: How are idealizations used in explanations?. Do these explanations have any peculiar characteristics—characteristics not shared by deductive-nomological explanations? If we assume that idealizations are false or “do not obtain,” how is it that they can have any explanatory power?. Further, there are questions of more general philosophic concern. How do the problems of idealizations relate to those of simplicity, for an idealization seems to be, in some sense, a type of simplification? How do the problems of ideal laws and theories relate to the general problems of scientific laws and theories? (shrink)

In this paper I show that Goodman's theory of projectibility, although partly successful, is inadequate since it fails to take into consideration the "approximate" nature of certain scientific hypotheses.