Since the appearance of T. S. Kuhn's The Structure of Scientific Revolutions, scholars from various fields have sought to evaluate their disciplines in the light of Kuhnian criteria for scientific change. In this paper I argue that a new paradigm seems needed in high energy physics, and that there is no more reason to say that matter is made of elementary particles, than to say that it is not. My argument, that high energy physics is approaching a state of crisis, (...) and that a new paradigm is needed, is based on an examination of two events which, according to Kuhn, presage a conceptual revolution: (1) the "old" paradigm of normal science becomes unclear; and (2) this paradigm fails to support normal problem solving research, and scientists begin to use it as if it were merely definitional. After examining the elementary particles paradigm in the light of these two criteria, I conclude that high energy physics is moving from "normal science" to "extraordinary science." I argue neither that a new paradigm has been found, nor that a return to normal science is imminent; instead I attempt to briefly outline some of the conceptual problems in high energy physics to which Heisenberg, Feynman, and others have alluded, but which so far have not been spelled out in any great philosophical detail. No attempt is made to argue about what the specific consequences of these difficulties might be, but merely to begin to clarify the problems facing scientists dealing with elementary particles. (shrink)