Kant on Wheels
- The Road since Structure: Philosophical Essays, 1970-93 by Thomas Kuhn, edited by James Conant and John Haugeland
Chicago, 335 pp, £16.00, November 2000, ISBN 0 226 45798 2
- Thomas Kuhn: A Philosophical History for Our Times by Steve Fuller
Chicago, 472 pp, £24.50, June 2000, ISBN 0 226 26894 2
At a New York cocktail party shortly after the war, a young and insecure physics postgraduate was heard to blurt out to a woman he had met there: ‘I just want to know what Truth is!’ This was Thomas Kuhn and what he meant was that specific truths such as those of physics mattered less to him than acquiring metaphysical knowledge of the nature of truth. Soon afterwards, he gave up physics, but rather than take up philosophy directly, he approached it by way of the history of science. The work that followed, especially The Structure of Scientific Revolutions, published in 1962 and now with sales of well over a million copies, makes his the most important contribution to the history and philosophy of science of the 20th century.
Kuhn was struck by the consensus among those working in particular disciplines during periods of what he came to call ‘normal science’. It isn’t just that they accept the same theories and data, they also have a shared conception of how to proceed in their research, a tacit agreement about where to look next. There is agreement about which new problems to tackle, what techniques to try and what count as good solutions. It is rather as if new practitioners in a particular discipline are covertly given copies of a book of rules, the secret guide to research in their field. But no such rulebooks exist. Kuhn wanted to find out what does the job of the rules that aren’t there.
What he found was that scientists learn to proceed by example rather than by rule. They are guided by what Kuhn called their exemplars, or certain shared solutions to problems in their speciality, like the problem sets that science students are expected to work through. (‘Exemplar’ captures the most important sense of Kuhn’s famous multivalent term, ‘paradigm’.) The function of problem sets is not to test students’ knowledge but to engender it. Similarly, exemplars guide research scientists in their work, for although, unlike rules, they are specific in content, they are general in their import. Scientists will choose new problems that seem similar to the exemplary ones, will deploy techniques similar to those that worked in the exemplars, and will judge their success by the standards the exemplars exemplify.
This idea of the co-ordinating and creative power of exemplars provided Kuhn with the basis for his general model of how sciences develop. Any new area of scientific inquiry must do without exemplars to start with and hence without the co-ordination of normal science. If suitable exemplars are eventually found, normal science can proceed. But exemplars sow the seeds of their own destruction, since they will eventually suggest problems that are not soluble by the exemplary techniques. This leads to a state of crisis and in some cases to a scientific revolution, where new exemplars replace the old ones and another period of normal science begins.
A scientific revolution is more disruptive than a simple replacement of one theory by a better one, because the theories held on either side of it are not just incompatible, they are ‘incommensurable’. In Structure, Kuhn used that term to refer to various factors that make the evaluation of competing theories problematic. Scientific revolutions are not irrational episodes, they are stages of enquiry where rationality becomes a much more complex and messy business than during periods of normal science. This is so in part because straightforward argument requires many shared premises, which are what normal scientists enjoy and revolutionary scientists lack.
Vol. 23 No. 16 · 23 August 2001
Peter Lipton concludes his review of my book Thomas Kuhn: A Philosophical History of Our Times (LRB, 19 July) by saying that ‘it’s not enough to investigate the causes and effects of Kuhn’s claims … we need to figure out whether they’re right.’ Would that the task were so simple! Lipton overlooks the fact that Kuhn’s pronouncements were subject to a very wide range of interpretations, virtually all of which he disowned – and rightly so. Moreover, most of those who interpreted Kuhn sympathetically ended up disappointed by the subsequent turns in his thought, as he increasingly avoided the radical-sounding social and political terms introduced in The Structure of Scientific Revolutions. Yet it is this comedy of errors that has led us to take Kuhn so seriously. I do not see how a purely philosophical analysis of Kuhn’s ideas could illuminate this point. Even if it turns out that Kuhn’s unpublished final work is revolutionary, that would not justify our having taken his work so seriously in the first place. At most, it would demonstrate that widespread confusion and misunderstanding eventually led us to a better account of science. Epistemologically speaking, this is no better than chancing on rain after a sufficiently long raindance.
University of Warwick
Vol. 23 No. 17 · 6 September 2001
Steve Fuller (Letters, 23 August) rejects my suggestion that we should try to figure out whether Thomas Kuhn's account of science is correct, on the grounds that Kuhn's work is difficult to interpret and he changed his mind. I think both the difficulty and the change are often exaggerated, but it doesn't really matter. In my review, I presented a common interpretation of Kuhn, according to which he offered an account of science that is deep, challenging and potentially very enlightening. Fuller may be worried about whether that account is truly Kuhn's, but that is irrelevant to the question of whether it is true.
University of Cambridge
As a former student of Thomas Kuhn, I would like to correct a common misunderstanding of his philosophy of science that is perpetuated in Peter Lipton’s review of his posthumous publication (LRB, 19 July). It is widely believed that Kuhn believed that theoretical ‘anomalies’ trigger crises, paradigm shifts or scientific revolutions. Although it is trivially true that during theoretical crises anomalies are implicated, it is more significantly true that anomalies are also present during long periods of normal research and do not provoke crises. Kuhn emphasised that while such anomalies, or ‘counterinstances’, occur frequently, paradigm shifts occur rarely. In Kuhn’s view what we, in retrospect, see as destructive anomalies, contemporary scientists, immersed in an apparently successful research tradition, count among the ‘puzzles’ that guide the programme of research. And even when an anomaly is implicated in a crisis, the result is not always a paradigm shift. Kuhn drew attention to two other possibilities: ‘sometimes normal science ultimately proves able to handle the crisis-provoking problem despite the despair of those who have seen it as the end of an existing paradigm’; or, if the anomaly is exceptionally intractable, it is ‘set aside for a future generation with more developed tools’.
What kinds of anomaly occasionally ‘evoke crisis’? Kuhn’s less than satisfactory answer was that a crisis-provoking anomaly ‘must determine the timing of breakdown’. And elsewhere he wrote that putting together the ‘internal approach’ and the ‘external approach’ in the study of the history of science ‘is perhaps the greatest challenge now faced by the profession, and there are increasing signs of a response’. To Kuhn’s dismay this response included the radical contention that science only reflects social and political interests and never makes contact with nature or reality. During the last years of his life Kuhn distanced himself from this ‘absurd’ claim – ‘deconstruction gone mad’.
Stevens Institute of Technology, Hoboken, New Jersey