Listener 19^th April 1984

The return of Grand Theory III: Barry Barnes on Thomas Kuhn

Challenging the Rationalist Myth

Thomas Kuhn's devastating critique of the methods by which scientific knowledge is produced has major implications for the way we think about 'knowledge' in general. Barry Barnes, Reader in the Department of Sociology at the University of Edinburgh, introduces the work of this influential American thinker .

            Thomas Kuhn is one of the few historians of science whose work is well known outside the field. His book on The Structure of Scientific Revolutions, published in 1962, has become a classic, a routine point of reference for discussion and debate throughout our culture generally. Needless to say, the book is more than an historical narrative. It takes the findings of historical research as the basis for a startlingly original account of the general nature of scientific knowledge. This has given the book a profound philosophical significance, at least in the English-speaking world, where science has always occupied a special position in our philosophical thinking.

We have never been able to accept the frankly speculative approach of the Continental philosophers, or their grand metaphysical theories. In Anglo-Saxon philosophy we have sought to assert only what we could justify, and our standards of justification have been demanding ones, modelled, we have believed, upon the stringent standards of justification of natural science. Science has served as our paradigm of knowledge, so that we have fastened upon any general account of science as an epistemology, an account of how knowledge as a whole should be acquired and evaluated.

            Simply by virtue of its subject, therefore, Kuhn's book was of considerable philosophical interest. But it was the treatment he gave of that subject which established his importance. Kuhn offered a unique combination of scholarship and iconoclasm. Although scarcely anyone initially accepted his radically unorthodox philosophical treatment of science, it commanded respect because of the acknowledged competence of the historical work on which it was based. Kuhn was quickly, recognised as a brilliant devil's advocate, a formidable critic of established philosophical wisdom.

            If we are to understand the full significance of Kuhn's work, we must look first to this established wisdom. It is no mere abstract philosophy which Kuhn calls into question, rather, it is a connected pattern of ideas and evaluations which, together, constitute a key component of our generally accepted modern world-view. Although the pattern is a complex one, incorporating elements of rationalism, individualism and the liberal faith in gradual evolutionary progress, I shall simply call it the myth of rationalism.

            Rationalist doctrines emphasise the power of the reasoning capabilities which all individuals possess. Rationalist accounts of science see its growth as the product of individual acts of reasoning. By logical inference on the basis of their experience, individual scientists contribute to scientific progress, to the cumulative development of scientific know-ledge and its gradually increasing correspondence with the reality it describes.

            Only if individuals cease to be rational is progress threatened. The danger here is society. Social pressures, political passions, economic interests may bias the judgment of the individual, so that he irrationally refuses to modify a cherished belief, or to accept a disagreeable one. Over time, these biases may transform thought into political ideology or religious dogma: they must be eliminated or neutralised if the understanding of nature is to be advanced, or a contribution to science made.

            This very rudimentary rationalist account is widely accepted, not just in philosophy but in  society at large. Note how nicely it blends with the central political values of our modern liberal democratic societies. It sets men before nature just as they stand before our law, as equals. Reason, the possession of every man, is all that is needed to derive knowledge from experience. Everyone can do it alike. Equally important, there is a strongly individualistic emphasis in the rationalist account: progress flows from unconstrained individual decisions just as is claimed by the current theories of our Treasury economists; and social interference introduces undesirable distortions into the system.

            Finally, the rationalist account reflects the cherished liberal ideal of gradual evolutionary change: scientific progress stands, in this respect, as a gratifying analogue of social progress. This is why I spoke earlier of the myth of rationalism; not to imply that rationalism is false, but to imply that it is generally believed as a myth is believed - because of its happy congruity with other patterns of thought and activity.

            Needless to say. professional philosophers have not been content simply to assume and develop the rationalist viewpoint: they have also thoroughly analysed it, seeking its weaknesses and deficiencies. Some the most powerful anti-rationalist arguments have been developed by rationalist philosophers themselves.

            The most significant of these arguments, recognised Achilles' heel of rationalism, derives from the theoretical character of scientific- knowledge. Scientists invariably describe and explain phenomena in terms of a specific theory which they have invented or constructed. But, formally speaking, an endless number of theories can be constructed be consistent with a particular body of data, just as an endless number of curves always be constructed to pass through any finite number of points. Logically. the notion of a single correct, or best-supported, theory is an extremely dubious one; but, historically it is a notion which scientists routinely and effectively employ - which is, indeed, essential in scientific research.

            The problem of the logical underdetermination of scientific theories is not denied by rationalist philosophers; but they do betray their prejudices in the way that they treat it. They assume that rationalism must be correct and that the problem it faces is therefore a minor difficulty-something which will eventually be resolved, even if we cannot see how at present.

            Kuhn's attitude to this same difficulty could not be more different. Like the rationalists, he cannot see how scientists reason securely from the data to the correct theory. But this leads him to ask whether the theory might not be accepted on some other basis. And to check this, he turns to examine the practice of scientists, largely as it is set out and recorded in historical materials.

Kuhn investigates what research is typically like, most of the time, in any well-established and productive scientific field. It is, he concludes, largely devoted to the elaboration and extension of some generally accepted concrete scientific achievement. Such an achievement is the worked-out solution to a particular scientific problem or puzzle. It embodies both theory and technique, and shows by example how they should be used. Think, for example, of Mendel's work with pea plants, or Bohr's on the spectrum of hydrogen. An accepted achievement of this kind may solve but a single scientific problem, and solve it crudely and incompletely at that. But it will have been selected not for its present condition but its future promise, and its many weaknesses will simply be treated as temporary aberrations, the removal of which is part of the task of future work. The attraction of the achievement is indeed that it can serve as the basis for further research. Scientists give it the status of an authoritative model - a scientific paradigm, as Kuhn says - and they develop their own research around it and in analogy with it. Kuhn calls this kind of research 'normal science'.

            Kuhn stresses that the paradigm for normal science is never accepted purely out of logical consideration. There is always evidence which supports it and evidence which calls it into question; argument for and argument against. It is used in research by agreement, not because it has been proved. And the research wherein it is used assumes it, and does not attempt its proof. In normal science, the paradigm is never judged or tested: it itself is the basis for judgment. Successful use of the paradigm adds to our knowledge of nature; unsuccessful use of the paradigm merely indicates the incompetence of the scientists, or the inadequacies of their equipment, or the existence of some unknown source of disturbance of the conditions of observation or experiment. The paradigm serves as the conventional basis for the evaluation of research: normal science relies upon consensus. not logical compulsion.

            Indeed, as Kuhn is at pains to stress, the consensual character of normal science goes yet deeper than this. Although the paradigm serves as the basis for the evaluation of research, there is no fixed and predetermined way of using it for this task. The paradigm, remember, is a scientific achievement, not a set of watertight instructions for assessing other achievements. It is used much as a precedent is used in a court of law: scientists actively interpret its significance and agree between themselves what its implications are. Thus, scientists doing normal science do not merely have to agree upon what should serve as the basis of their work; they have to agree upon how it should serve that purpose in every particular case. Every single step becomes a matter for negotiation on the basis of custom and convention. Nothing could make a stronger contrast with the normal rationalist view.

            Needless to say, what has been said so far is incomplete. We still need to know how scientists become committed to a paradigm in the first place, and how that commitment is maintained. This becomes intelligible when we recognise that science is a form of culture handed down from generation to generation. Then we can see that commitments in science are inculcated and maintained in just the same way as commitments to other aspects of our way of life. For most scientists, paradigms are the inherited knowledge passed on to them in the period of their scientific apprenticeship. Intense commitment to the paradigms, and a minimal inclination to think or act outside of them, is systematically encouraged at this time, by what Kuhn regards as a highly dogmatic and authoritarian process of training. And it is subsequently maintained by a developed system of social control.

            Kuhn relates decisions to change a paradigm to the social psychology of the scientific group involved; and he insists that such changes can never be accounted for by purely logical considerations. Just as logic cannot compel the group to stay with a paradigm, so it cannot compel them to leave it for another.

            Every system of normal science is, to a large extent, self-validating: its paradigm is supported and confirmed by a practice which assumes its truth or applicability, and adjusts to that assumption. Thus, every such paradigm can be presented by its adherents as consistent with the real world, and defended in its own terms against attempted refutations. Nor is there any unproblematic external standard with which to compare competing paradigms, any common measure to set against both of them, which all rational men would accept as appropriate. Paradigms, according to Kuhn, are incommensurable. And because of this incommensurability it is not possible to provide a logically satisfactory account of scientific progress, or even of the difference between revolutions in the scientific and the political spheres.

It will be clear by now that Kuhn's work uncompromisingly and comprehensively undermines the rationalist account of science. Given the general acceptance of liberal-rationalist modes of thought in our society, it's not altogether surprising that Kuhn's work has occasionally been interpreted as anti-scientific polemic, and that it attained a certain celebrity among radical critics of science when it first appeared in the 1960s.

            In fact, of course, Kuhn had merely examined what he took for granted to be man's finest intellectual achievement. Far from attacking science for its failure to meet the standards of rationalism. he destroyed the credibility of the rationalist mythology by exposing its incongruity with science: science itself remained firmly fixed upon its pedestal.

            Kuhn was misunderstood. I suspect, because the general standpoint from which he wrote had become unfamiliar to us, just as most standpoints which allow the fundamental criticism of liberal-rationalistic modes of thinking have become unfamiliar. His work has a place within a long tradition of conservative thought which had its finest flowering in the 19th century. but which is still far from extinct. Where rationalism speaks of reason and the individual, this old style of conservatism speaks of custom and community. And it speaks of custom and community, not to undermine and condemn, but to support and commend. Kuhn's account of the conventional character of science is not an account of how science falls short of being knowledge, it is an account of how it attains that status.

            In many ways it is ironical that this discussion of Kuhn should form part of a series on the return of grand theory. For all the scale of his vision, Kuhn has always been uneasy in the role of a speculator, and positively averse to metaphysical posturing. He is himself imbued with the caution and restraint which runs through the Anglo-Saxon philosophical tradition: his mental universe could scarcely be more distant from that of Althusser or even Habermas.

            This, however, is precisely why Kuhn does deserve his place in this series. He has exposed the defects of rationalism in an idiom acceptable to those who assume it or defend it. And thus in societies like ours, where myth of rationalism thoroughly permeates everyday habits of thinking, his work has played a major part in clearing the path for more promising lines of thought.

            Traditionally, we have sought to understand the advancement of scientific knowledge purely in terms of reason and experience – in terms of the general logical operations which any man may perform and the empirical observations which any man may make. As to the remainder of the human condition, that has been of interest only as a way of understanding the biases and distortions which impede progress.

            We are now well on the way to discarding this intolerably narrow view, and recognising that to understand our knowledge and its basis we must achieve a more comprehensive self-understanding. We need, in particular, to understand ourselves not simply as organisms, but as communities. This is because knowledge is, in its very nature, a collective creation, founded not upon isolated individual judgments but upon the evaluations we make together in social situations, according to custom and precedent, and in relation to our communal ends. Even scientific inference must be seen as guided by custom and convention, and not treated purely as manifestations of the universal reason of the  individual. It is not so much that custom must replace reason in our thinking, as that reasoning must be seen as a profoundly conventional activity. Our hitherto impoverished conception of reason must be enlarged.

            Precisely this has been the aim, if not the achievement of much of the grand the Continental philosophers. It's good to note an increase of interest in these within the English-speaking world, and a growing understanding of their objective. The result must be an enrichment of our own thought. At the same time, it may be that we shall eventually offer our own distinctive contribution to their project. For it is scarcely likely that, as we explore the work of Habermas or Althusser, we shall lose our traditional concern for evidence and justification. And it is precisely in its comparative lack of that concern that the major weakness of the literature of grand theory currently lies.

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A similar paper is to be found in:

Q. Skinner (editor), The Return of the Grand Theory in the Human Sciences, Cambridge Univ. Press, 1985.