Popper and the logical empiricists focused on the logical status of the products of research and made scientific discovery and invention, the processes of achieving creative breakthroughs, exogenous to the logic of science. Creative insights were the result of happy but accidental psychological experiences, of minimal cognitive interest. Kuhn, in Structure, attempted to endogenize discovery, to provide an account of the practice of scientific problem-solving but without employing traditional logic of discovery or justification. Key to his account of normal science was the role of exemplars (standardized problem solutions) and acquired resemblance relations (analogies, metaphors, similes). Kuhn’s account was insightful in suggesting that puzzle solving amounts to rhetoric-based problem reduction to existing exemplars, largely independent of theory reduction. While Kuhn helped to resurrect philosophical interest in the process of research, he was only partially successful. By taming discovery in normal science, he exacerbated his problem of understanding how revolutionary breaks are conceived. And he left us with several questions about exemplars. What, exactly, are exemplars and where do they come from? Can exemplars carry across revolutionary breaks? I employ examples from early quantum theory.

Every essay in this book has been written especially for this volume. While the book is aimed at a general educated audience, each author aspires to say something sufficiently substantial about one or more dimensions of Kuhn's work to interest experts. Moreover, this is more than a retrospective on Kuhn's work. It is forward-looking as well, with an eye on ongoing developments in philosophy of science, epistemology, social studies of science, and especially the cognitive sciences. Given our space limitations, we focus on Kuhn the philosopher of science rather than Kuhn the historian, and we devote more attention to Kuhn's relation to cognitive science than to social studies of science.

I owe the idea for the project to Terry Moore, Publishing Director for Humanities at Cambridge University Press, New York. Terry conceived the timely new series Contemporary Philosophy in Focus, with this book being one of the first offerings. I appreciate his guidance as to what sort of book it should be. Thanks to production editor Louise Calabro and to copyeditor Helen Greenberg, who gave the volume its final form. Thanks also to my wife, Dr. Gaye McCollum-Nickles, for helpful comments on my own contributions to the volume.

The decision of which authors to include in such a volume is always difficult and somewhat arbitrary. Several outstanding expositors and/or critics of Kuhn had to be passed over in order to keep the volume to a manageable size and to achieve a wider diversity of perspectives on Kuhn's work.

INTRODUCTION

The central distinction of Thomas Kuhn's The Structure of Scientific Revolutions (1962) is that between normal science and revolutionary science. He offered suggestive and provocative but sketchy accounts of both. Most historians and sociologists who have discussed Kuhn's work have maintained that his account of normal science is the more important, while philosophers and culture theorists – and Kuhn himself – have tended to regard his claims about revolutionary discontinuities and incommensurability as his truly original contribution. In my judgment, the problems that Kuhn engaged in his account of normal science are more heuristically promising for understanding scientific inquiry and human inquiry more generally. Subsequent developments in cognitive psychology have vindicated Kuhn's departures from standard theories of cognition. It may even be the case that what is worth saving in Kuhn's treatment of revolutions depends on the account of cognition that he developed for normal science. After all, Kuhn's own most informative characterization of revolutionary science is that it is extraordinary – nonnormal. Accordingly, I shall examine Kuhn's account of normal scientific cognition as puzzle-solving practices guided by the exemplary problem solutions that he called “exemplars,” together with what he termed “an acquired similarity relation.” I shall center my discussion on that most basic problem concerning the very possibility of inquiry – the Meno paradox – and indicate how Kuhn's account of scientific inquiry attempts to solve it. Here I must limit myself to the “early” Kuhn of Structure and the related essays written in the 1960s and 1970s.

Whether one is pro-Kuhn, anti-Kuhn, or neutral, no one can deny that the work of Thomas Kuhn has been a lightning rod for debates about science, culture, and policy across many academic fields – and even in the political arena and the business world. This is especially true of Kuhn's best-known work, The Structure of Scientific Revolutions, originally published in 1962 and expanded in 1970. By now the book has sold over a million copies in two dozen languages – numbers almost unheard of for an academic book about abstract philosophical topics. The wide reception of his work, which greatly surprised Kuhn himself, has elevated the terms “paradigm,” “paradigm change,” and “paradigm shift” to household phrases and the stuff of advertising slogans, corporate boardrooms, and Washington bureaucratese. Although diverse individuals and groups have read and used (or misused!) it very differently, each according to their own abilities and needs, Kuhn's work has the merit, in these fragmented times, of serving as a common reference point and of generating cross-disciplinary discussion.

When Kuhn began writing, philosophy of science, especially in England and the United States, was dominated by the logical positivists (Rudolf Carnap, Hans Reichenbach, Carl Hempel, and others) and by Karl Popper and his followers. In The Structure of Scientific Revolutions (Structure hereafter), Kuhn gave us a very different picture of science. Kuhn contended that there are two types of mature physical science, “normal science” and “extraordinary” or “revolutionary science.