Sunday, October 4, 2009

Kuhn's paradigm shift

Thomas Kuhn's The Structure of Scientific Revolutions (1962) brought about a paradigm shift of its own, in the way that philosophers thought about science. The book was published in the Vienna Circle's International Encyclopedia of Unified Science in 1962. (See earlier posts on the Vienna Circle; post, post.) And almost immediately it stimulated a profound change in the fundamental questions that defined the philosophy of science. For one thing, it shifted the focus from the context of justification to the context of discovery. It legitimated the introduction of the study of the history of science into the philosophy of science -- and thereby also legitimated the perspective of sociological study of the actual practices of science. And it cast into doubt the most fundamental assumptions of positivism as a theory of how the science enterprise actually works.

And yet it also preserved an epistemological perspective. Kuhn forced us to ask questions about truth, justification, and conceptual discovery -- even as he provided a basis for being skeptical about the stronger claims for scientific rationality by positivists like Reichenbach and Carnap. And the framework threatened to lead to a kind of cognitive relativism: "truth" is relative to a set of extra-rational conventions of conceptual scheme and interpretation of data.

The main threads of Kuhn's approach to science are well known. Science really gets underway when a scientific tradition has succeeded on formulating a paradigm. A paradigm includes a diverse set of elements -- conceptual schemes, research techniques, bodies of accepted data and theory, and embedded criteria and processes for the validation of results. Paradigms are not subject to testing or justification; in fact, empirical procedures are embedded within paradigms. Paradigms are in some ways incommensurable -- Kuhn alluded to gestalt psychology to capture the idea that a paradigm structures our perceptions of the world. There are no crucial experiments -- instead, anomalies accumulate and eventually the advocates of an old paradigm die out and leave the field to practitioners of a new paradigm. Like Polanyi, Kuhn emphasizes the concrete practical knowledge that is a fundamental component of scientific education (post). By learning to use the instruments and perform the experiments, the budding scientist learns to see the world in a paradigm-specific way. (Alexander Bird provides a good essay on Kuhn in the Stanford Encyclopedia of Philosophy.)

A couple of questions are particularly interesting today, approaching fifty years after the writing of the book. One is the question of origins: where did Kuhn's basic intuitions come from? Was the idea of a paradigm a bolt from the blue, or was there a comprehensible line of intellectual development that led to it? There certainly was a strong tradition of study of the history of science from the late nineteenth to the twentieth century; but Kuhn was the first to bring this tradition into explicit dialogue with the philosophy of science. Henri Poincaré (The Foundations of Science: Science and Hypothesis, The Value of Science, Science and Methods) and Pierre Duhem (The Aim and Structure of Physical Theory) are examples of thinkers who brought a knowledge of the history of science into their thinking about the logic of science. And Alexandre Koyré's studies of Galileo are relevant too (From the Closed World to the Infinite Universe); Koyré made plain the "revolutionary" character of Galileo's thought within the history of science. However, it appears that Kuhn's understanding of the history of science took shape through his own efforts to make sense of important episodes in the history of science while teaching in the General Education in Science curriculum at Harvard, rather than building on prior traditions.

Another question arises from the fact of its surprising publication in the Encyclopedia. The Encyclopedia project was a fundamental and deliberate expression of logical positivism. Structure of Scientific Revolutions, on the other hand, became one of the founding texts of anti-positivism. And this was apparent in the book from the start. So how did it come to be published here? (Michael Friedman takes up this subject in detail in "Kuhn and Logical Positivism" in Thomas Nickles, Thomas Kuhn (link).) George Reisch and Brazilian philosopher J. C. P. Oliveira address exactly this question. Oliveira offers an interesting discussion of the relationship between Kuhn and Carnap in an online article. He quotes crucial letters from Carnap to Kuhn in 1960 and 1962 about the publication of SSR in the Encyclopedia series. Carnap writes,
I believe that the planned monograph will be a valuable contri­bution to the Encyclopedia. I am myself very much interested in the problems which you intend to deal with, even though my knowledge of the history of science is rather fragmentary. Among many other items I liked your emphasis on the new conceptual frameworks which are proposed in revolutions in science, and, on their basis, the posing of new questions, not only answers to old problems. (REISCH 1991, p. 266)

I am convinced that your ideas will be very stimulating for all those who are interested in the nature of scientific theories and especially the causes and forms of their changes. I found very illuminating the parallel you draw with Darwinian evolution: just as Darwin gave up the earlier idea that the evolution was directed towards a predeter­mined goal, men as the perfect organism, and saw it as a process of improvement by natural selection, you emphasize that the develop­ment of theories is not directed toward the perfect true theory, but is a process of improvement of an instrument. In my own work on in­ductive logic in recent years I have come to a similar idea: that my work and that of a few friends in the step for step solution of prob­lems should not be regarded as leading to “the ideal system”, but rather as a step for step improvement of an instrument. Before I read your manuscript I would not have put it in just those words. But your formulations and clarifications by examples and also your analogy with Darwin’s theory helped me to see clearer what I had in mind. From September on I shall be for a year at the Stanford Center. I hope that we shall have an opportunity to get together and talk about problems of common interest. (REISCH 1991, pp.266-267)
Against what Oliveira calls "revisionist" historians of the philosophy of science, Oliveira does not believe that SSR was accepted for publication by Carnap because Carnap or other late Vienna School philosophers believed there was a significant degree of agreement between Kuhn and Carnap. Instead, he argues that the Encyclopedia group believed that the history of science was an entirely separate subject from the philosophy of science. It was a valid subject of investigation, but had nothing to do with the logic of science. Oliveira writes,
Thus, the publication of Structure in Encyclopedia could be justified merely by the fact that the Encyclopedia project had already reserved space for it. Indeed, it is worth pointing out that the editors commissioned Kuhn’s book as a work in history of science especially for publication in the Encyclopedia.
Also interesting is to consider where Kuhn's ideas went from here. How much influence did the theory have within philosophy? Certainly Kuhn had vast influence within the next generation of anti-positivist or post-positivist philosophy of science. And he had influence in fields very remote from philosophy as well. Paul Feyerabend was directly exposed to Kuhn at UCLA and picks up the anti-positivist thread in Against Method. Imre Lakatos introduces important alternatives to the concept of paradigm with his concept of a scientific research programme. Lakatos makes an effort to reintroduce rational standards into the task of paradigm choice through his idea of progressive problem shifts (The Methodology of Scientific Research Programmes: Volume 1: Philosophical Papers). An important volume involving Kuhn, Feyerabend, and Lakatos came directly out of a conference focused on Kuhn's work (Criticism and the Growth of Knowledge: Volume 4: Proceedings of the International Colloquium in the Philosophy of Science, London, 1965). Kuhn's ideas have had a very wide exposure within the philosophy of science; but as Alexander Bird notes in his essay in the Stanford Encyclopedia of Philosophy, there has not emerged a "school" of Kuhnian philosophy of science.

From the perspective of a half century, some of the most enduring questions raised by Kuhn are these:
  • What does the detailed study of the history of science tell us about scientific rationality?
  • To what extent is it true that scientific training inculcates adherence to a conceptual scheme and approach to the world that the scientist simply can't critically evaluate?
  • Does the concept of a scientific paradigm apply to other fields of knowledge? Do sociologists or art historians have paradigms in Kuhn's strong sense?
  • Is there a meta-theory of scientific rationality that permits scientists and philosophers to critically examine alternative paradigms?
  • And for the social sciences -- are Marxism, verstehen theory, or Parsonian sociology paradigms in the strong Kuhnian sense?
Perhaps the strongest legacy is this: Kuhn's work provides a compelling basis for thinking that we can do the philosophy of science best when we consider the real epistemic practices of working scientists carefully and critically. The history and sociology of science is indeed relevant to the epistemic concerns of the philosophy of science. And this is especially true in the case of the social sciences.

Reisch, George (1991). Did Kuhn Kill Logical Empiricism? Philosophy of Science, 58.


Burk Braun said...

Hi, Daniel-

Let me take you up on some of those questions. Firstly, Kuhn's ideas apply to any area of knowlege, even to areas of non-knowledge, even BS, insofar as they have rote and habitual ways of conceptualizing things or talking about things. I think that (i.e. groupthink) characterizes all fields, including business and economics, as we find recently, even religion, etc. The paradigms might not be as richly detailed and conceptualized, but they are just as immovable.

This also indicates that science has two significant advantages in overcoming its own problems of "stuck" paradigms- the rich and detailed content of scientific paradigms that make then susceptible to explicit anomalies and difficulties (i.e. to the point of being expressed mathematically), and more importantly, the intellectual rigor to test hypotheses, accept the empirical standard, and accept new and changed information/models.

So my position is that, while it is true that scientific training does inculcate adherence to various conceptual schemes, but that they can also evalute them, since the overall ethic and rigor of science supercedes the paradigms at work. While I agree with Kuhn generally, I am more optimistic, since practicioners vary substantially in their ability to adopt new paradigms. Some people are hopeless and do indeed have to die off rather than change their minds, but many others are quite capable of changing their minds, so the field goes in new directions, if more slowly than optimal.

Plate tectonics may have taken a few years to take the scientific field by storm, but it did so in less than a generation, and the same is true of countless other changes, like various paradigms of cancer etiology, the etiology of ulcers, etc. The more thorough-going and bizarre the new paradigm is, the more difficult it is to displace the current system, but caution is surely warranted to some degree.

The various current deep controversies, like the nature of dark energy, the missing mass of the universe, and the nature of consciousness, the multiverse hypothesis, string theory, etc. all suffer from a lack of data above all. There may be clever or balmy paradigms out there waiting to explain these conundra, but the fields are in a state of acknowledged suspension because nothing compelling has yet emerged, either on the theory side or on the data side.

Matt said...

You're surely right to say that the largest legacy of Kuhn's book was to shift the focus of philosophy of science onto the practices of scientists. One thing that I think is easy to overlook is the dual or twin nature of a paradigm.

I think the largest thrust (such as Lakatos, Laudan, etc.) of post-Kuhnian research within philosophy involved thinking of a paradigm as a conceptual scheme. However, a conceptual scheme is merely one way of working out *one part* of what a paradigm is supposed to be, on Kuhn's account.

Before the 1970's (after which I'm not really sure Kuhn himself was any longer clear on what a paradigm is supposed to be), Kuhn was fairly clear that a paradigm has a dual nature. It is both a practice/event, and a way of thinking about that practice/event. Calling a paradigm a conceptual scheme is, of course, one way of fleshing this out. But a paradigm can also be something much less formal, and Kuhn's examples in Structure often highlighted this. A paradigm was most often a general way of thinking about the field that was not set out explicitly.

This latter sense of paradigm was, I think, the one that had the most import to the philosophy of social science, particularly Polanyi and the Edinburgh/Bath schools.

Anonymous said...

hi, I'm looking at the advantages of the application of Kuhn in social sciences and was quite caught by this line in your blog- "For one thing, it shifted the focus from the context of justification to the context of discovery." by any chance do you have a reference for it?

Thank you,

Daniel Little said...

This is one of the basic branches between logical positivist philosophy of science and post-positivist philosophy of science. Positivists focused on justification, whereas more historically minded (and research-community minded) philosophers and historians were at least as interested in the process of science and the ways in which a scientific research community operates. See Imre Lakatos's work on the methodology of scientific research programmes.