Marxism and scientific revolutions

How are scientific paradigms established? And what does this mean for the politics of the working class? Chris Knight examines the issues

In my article last week, I showed how Marx and Engels viewed science (Weekly Worker September 28). They saw it as humanity's only genuinely internationalist form of knowledge. The idea of subordinating science to a political party - even to a party calling itself 'communist' - would have been anathema to them. It is not that science must be subordinated to the Communist Party. On the contrary, the Communist Party must be subordinated to science. It would not be a Communist Party otherwise.

In this week's article, my aim is to connect these ideas to the valuable insights of the great science historian, Thomas Kuhn.

One of the most important achievements of 20th century historical scholarship was Kuhn's major book, The structure of scientific revolutions.1 It would be difficult to overestimate the impact which this work has had on the sociology and philosophy of science.

Predictably, postmodernists have used Kuhn to justify their claim that there is no such thing as science - that everything boils down to politics and power. But Kuhn's work can justify precisely the reverse conclusion - that real science is possible only if scientists are powerful enough to resist class political pressure. The struggle for such autonomy, if this logic is pursued, turns out to be inseparable from the struggle for self-emancipation of the international working class.

In his great book, Kuhn's focus is not the relationship between scientific development and social or political events. His work concerns the internal structure of science. Nor does Kuhn accept any absolute distinction between science, on the one hand, and myth or ideology, on the other. For him, this distinction is always a relative one - a matter of the degree to which one conceptual system can produce agreement and prove fruitful in comparison with alternatives.

His main point is that a form of knowledge only acquires the status of 'science' by demonstrating that it can produce very fundamental levels of agreement between thinkers which are beyond the scope of rival systems of knowledge. Schools of thought which prove to be incapable of producing enduring levels of agreement - in scientific communities which cut across local or national barriers - tend not to be accorded the status of science. It is for this reason that 'social science' is so suspect. It seems to be incapable of producing any real agreement at all.

Setting the paradigm

In explaining how he came to work on the subject matter of his book, Kuhn writes: "... I was struck by the number and extent of the overt disagreements between social scientists about the nature of legitimate scientific problems and methods. Both history and acquaintance made me doubt that practitioners of the natural sciences possess firmer or more permanent answers to such questions than their colleagues in social science. Yet, somehow, the practice of astronomy, physics, chemistry or biology normally fails to evoke the controversies over fundamentals that today often seem endemic among, say, psychologists or sociologists."2

Kuhn's point is that in the social sciences thinkers not only cannot reach agreement with each other on fundamental issues - they cannot even find a common language of rules or concepts through which to communicate with each other in a rational way. There is a point at which rational debate breaks down and the opposing schools seem to each other to be breaking the rules and resorting to illegitimate techniques of persuasion, including even material inducements or force. In fact, it is not just that the rules are broken - it turns out that there are no rules. Each camp only obeys its own rules. This is in stark contrast to the normal situation among, say, nuclear physicists, who, even when they do disagree with each other on fundamental issues, nevertheless possess a shared language - a set of agreed rules of procedure, concepts, traditions and ideas through which fruitful communication can be achieved.

But Kuhn's most significant point is that the natural sciences themselves were once in a position similar in essentials to that of the social sciences today. They, too, in their early stages of development, were incapable of producing any enduring agreement or language on the basis of which a unified scientific community could form. And they, too - like the social sciences today - were divided by disagreements over fundamentals: disagreements which often seemed to be of a political or even violent kind.

On June 21 1633, Galileo de Galilei was interrogated by the pope and by a tribunal made up of cardinals and high officials of the catholic church who threatened him with torture unless he withdrew his allegation that the earth circled the sun. In those times, the conflict between the Ptolemaic and Copernican systems of astronomy was a political one and anyone supporting Copernicus risked persecution, imprisonment or even death by being burned at the stake. If this example seems historically remote, we should remember that Charles Darwin was considered to be putting forward a theologically dangerous and politically subversive theory when he argued that humanity was descended from a kind of ape.

In the case of both Galileo and Darwin, it was only the political and ideological defeat of the church on the issues concerned - defeats which formed part of a wider process of social and political change - which eventually lifted science from the realm of political controversy. But, conversely, it is only once its initial political coloration has faded away that science produces sufficient general agreement for it to be recognised simply as science. Borrowing from Marx, we might say that science has to "conquer politically" before it can "shed its political cloak".

Achievements such as those of Copernicus and Darwin are termed by Kuhn "paradigms". Paradigms are "universally recognised scientific achievements that for a time provide model problems and solutions to a community of practitioners".3 Such achievements are products of scientific revolutions. A revolution of this kind is not simply an addition to pre-existing knowledge. It is, within any given field, "a reconstruction of the field from new fundamentals ..."4 It is a complete demolition of an old theoretical and conceptual structure and its replacement by a new one based on entirely different interests, aims and premises.

During the course of a scientific revolution, nothing is agreed, there are no common rules of procedure, everything seems to be ideological, and political and other issues are decided by 'unconstitutional' means. The old paradigm is not defeated on the basis of its own rules, but is attacked from outside. It cannot be defeated on the basis of its own rules, for these rules are not only inadequate to solve the new problems which have begun to arise - they actually preclude any discussion of these problems at all.

For Kuhn, the parallelism with political and social revolutions was profound. He explains: "Political revolutions aim to change political institutions in ways that those institutions themselves prohibit. Their success therefore necessitates the partial relinquishment of one set of institutions in favour of another, and in the interim, society is not fully governed by institutions at all. Initially it is crisis alone that attenuates the role of political institutions ... In increasing numbers individuals become increasingly estranged from political life and behave more and more eccentrically within it.

"Then, as the crisis deepens, many of those individuals commit themselves to some concrete proposal for the reconstruction of society in a new institutional framework. At that point the society is divided into competing camps or parties: one seeking to defend the old institutional constellation; the others seeking to institute some new one. And, once that polarisation has occurred, political recourse fails. Because they differ about the institutional matrix within which political change is to be achieved and evaluated, because they acknowledge no supra-institutional framework for the adjudication of revolutionary differences, the parties to a revolutionary conflict must finally resort to the techniques of mass persuasion, often including force. Though revolutions have had a vital role in the evolution of political institutions, that role depends upon their being partially extra-political or extra-institutional events."5

It is just the same, writes Kuhn, when, in the course of a scientific revolution, scientists polarise into opposite camps. The opposing camps cannot communicate. They talk 'past' each other, questioning each other's most elementary premises and refusing to submit to each other's logical or procedural rules. In periods of 'normal science' - ie, in periods of consolidation which follow scientific revolutions, and during which all scientists in the field concerned accept the paradigm of the victorious party - everything can seem 'rational'. Because a community exists which bases itself on a set of shared assumptions and traditions, scientists can appeal to certain written or unwritten agreements as to what constitutes 'correct' or 'rational' procedure and what does not. Disputes internal to a single paradigm can be settled in an orderly way, on the basis of the rules laid down by that paradigm itself. This is what 'normal science' is all about.

But when an entire paradigm is being challenged from outside, there is no purely logical way to proceed. The supporters of the new paradigm may feel that their own framework is far more powerful, far simpler, more elegant and more logical than the old one of their opponents. But they cannot convince their adversaries on the basis of those opponents' own rules. If the old guard are to be won over, they must make a leap in abandoning their former conceptions as to what constituted 'proper' procedure:

"Like the choice between competing political institutions, that between competing paradigms proves to be a choice between incompatible modes of community life. Because it has that character, the choice is not and cannot be determined merely by the evaluative procedures characteristic of normal science, for these depend in part upon a particular paradigm, and that paradigm is at issue. When paradigms enter, as they must, into a debate about paradigm choice, their role is necessarily circular. Each group uses its own paradigm to argue in that paradigm's defence.

"The resulting circularity does not, of course, make the arguments wrong or even ineffectual. The man who premises a paradigm when arguing in its defence can nonetheless provide a clear exhibit of what scientific practice will be like for those who adopt the new view of nature. That exhibit can be immensely persuasive, often compellingly so. Yet, whatever its force, the status of the circular argument is only that of persuasion. It cannot be made logically or even probabilistically compelling for those who refuse to step into the circle. The premises and values shared by the two parties to a debate over paradigms are not sufficiently extensive for that. As in political revolutions, so in paradigm choice - there is no standard higher than the assent of the relevant community."6

Normal science and anomaly

It is not until a paradigm has been generally accepted that 'scientific research' in the normal sense can get underway. As Kuhn puts it, "Effective research scarcely begins before a scientific community thinks it has acquired firm answers to questions like the following: What are the fundamental entities of which the universe is composed? How do these interact with each other and with the senses? What questions may legitimately be asked about such entities and what techniques employed in seeking solutions?"7

Once - following a scientific revolution - a paradigm has become accepted, a period of conservatism sets in. This is a period of "mopping-up operations" - a period in which, over and over again, the validity of the new paradigm is 'proven'. Kuhn writes:

"Mopping-up operations are what engage most scientists throughout their careers. They constitute what I am here calling normal science. Closely examined, whether historically or in the contemporary laboratory, that enterprise seems an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies. No part of the aim of normal science is to call forth new phenomena; indeed those that will not fit the box are often not seen at all. Nor do scientists normally aim to invent new theories, and they are often intolerant of those invented by others."8

The paradigm validates itself again and again, in ever greater detail, by in effect forbidding scientists to investigate any problems other than those for which the paradigm offers a solution. Only problems whose solutions, like those of a crossword puzzle, are already "built in by their method of formulation are allowed". Other problems, as Kuhn writes, "including many that had previously been standard, are rejected as metaphysical, as the concern of another discipline, or sometimes as just too problematic to be worth the time."9

After about 1630, for example, and particularly after the appearance of Descartes' scientific writings, most physical scientists assumed that the universe was composed of microscopic corpuscles and that all natural phenomena could be explained in terms of corpuscular shape, size, motion and interaction. Hence the solar system was believed to function mechanically, like a clock. The same applied to all other systems, including living ones, such as animals. This paradigm was extremely powerful and led to immense advances of scientific knowledge, but it was also extremely narrow and limiting.

Anyone in Descartes' time who had drawn attention to, say, such phenomena as are nowadays associated with radioactivity simply could not have communicated in a coherent way. In that time, all the problems which today form the subject matter of nuclear physics would have seemed irrelevant, illegitimate, metaphysical and unscientific even to discuss. And, of course, none of these problems was discussed or even seen as a problem at all. Among scientists, it was 'known' what the universe was composed of. It was composed not of curved space-time nor electromagnetic fields, but very small, hard objects colliding in accordance with mechanical laws.

However, it is not for us simply to condemn the rigid, conservative paradigms which scientific revolutions eventually produce. Kuhn presents instead a subtle, dialectical argument, showing that it is precisely through such conservatism that new scientific revolutions themselves are prepared. Only a rigid, conservative, but extremely detailed and precise theoretical structure can be disturbed by some small finding which seems 'wrong'. It is only a community of scientists who confidently expect to find everything 'normal' who will genuinely know what an 'abnormality' or 'novelty' is - and who will be thrown into a crisis by it. A more easygoing, open-minded community which never expected precise regularities in the first place would not let themselves be bothered by such things. The precious anomaly in that case would be missed and science would not be in a position to learn from it or advance.

Just as state rigidity can build up pressure for social revolution, so normal science in its predictability and rigidity tends to stoke up pressure for scientific revolution. Every historian knows that a social revolution is often sparked by some apparently trivial incident in the workplace or street. In much the same way, some officially forbidden yet persistent laboratory result can trigger an explosion demolishing an entire scientific paradigm.

As Kuhn explains, "Without the special apparatus that is constructed mainly for anticipated functions, the results that lead ultimately to novelty could not occur. And even when the apparatus exists, novelty ordinarily emerges only for the man who, knowing with precision what he should expect, is able to recognise that something has gone wrong. Anomaly appears only against the background provided by the paradigm. The more precise and far-reaching that paradigm is, the more sensitive an indicator it provides of anomaly and hence of an occasion for paradigm change.

"In the normal mode of discovery, even resistance to change has a use ... By ensuring that the paradigm will not be too easily surrendered, resistance guarantees that scientists will not be lightly distracted and that the anomalies that lead to paradigm change will penetrate existing knowledge to the core."10

All scientific revolutions are precipitated by anomalies. A planet is in the wrong part of the sky. A photographic plate is clouded when it should not be. A fundamental law of nature is suddenly found to be wrong. A piece of laboratory equipment designed and constructed merely to add precision to a familiar finding behaves in a wholly unexpected way. To normal science, such anomalies are merely an irritation or a nuisance. In attempts to defend the old paradigm, efforts are made to suppress, obliterate or ignore the bothersome findings or events. New observations are made, new experiments are set up - with the sole intention of eliminating the anomaly concerned.

But it is precisely these attempts to defend the old paradigm which now begin to shake it to its foundations. Had the old, rigid paradigm not had its ardent defenders, the anomaly concerned would probably not even have been noticed. Now, however, an entire community of scientists begins to feel challenged by it, and more and more attention is focused upon it. Attempts are made to explain it away. But, the more such attempts are made, the more inconsistent and inadequate the old paradigm appears, the more strange the anomaly seems, and the more dissatisfied a section of the old scientific community becomes.

It is the internal inconsistencies now apparently permeating the old theoretical structure which convince some scientists - at first only a small number - that something is fundamentally wrong. Writing of astronomical observations, Copernicus complained that in his day astronomers were so "inconsistent in these investigations ... that they cannot even explain or observe the constant length of the seasonal year". He continued: ""¦ it is as though an artist were to gather the hands, feet, head and other members for his images from diverse models, each part excellently drawn, but not related to a single body, and, since they in no way match each other, the result would be a monster rather than man."11

In the period immediately preceding every scientific revolution, similar complaints are made. There is no neat, logical proof that the old paradigm is wrong. Rather there arises a general sense of dissatisfaction, a feeling - on the part of some - that absolutely everything is wrong, and a gradual splintering of the scientific community into schools and factions between whom communication is difficult or even impossible. Few things - not even the most elementary principles - seem to be agreed upon any more. Everything is questioned, anything is allowed.

"The proliferation of competing articulations," writes Kuhn, "the willingness to try anything, the expression of explicit discontent, the recourse to philosophy and to debate over fundamentals - all these are symptoms of a transition from normal to extraordinary research."12 All these are signs that the old theoretical edifice is crumbling and that a new one is about to take its place.

'Madness' of the new

But how does the new paradigm arise? Kuhn argues that it cannot arise logically out of the premises of the old one, because logic is a matter of symbolism - of the meaning of figures, equations and terms - whereas what is required is a complete restructuring of the semantic field itself. In fact, at first, logically it is unquestionably the old paradigm's defenders who are right:

"The laymen who scoffed at Einstein's general theory of relativity because space could not be 'curved' - it was not that sort of thing - were not simply wrong or mistaken. Nor were the mathematicians, physicists and philosophers who tried to develop a Euclidean version of Einstein's theory. What had previously been meant by space was necessarily flat, homogenous, isotropic and unaffected by the presence of matter. If it had not been, Newtonian physics would not have worked. To make the transition to Einstein's universe, the whole conceptual web whose strands are space, time, matter, force and motion had to be shifted and laid down again on nature whole. Only men who had together undergone or failed to undergo that transformation would be able to discover precisely what they agreed or disagreed about.

"Communication across the revolutionary divide is inevitably partial. Consider, for another example, the men who called Copernicus mad because he proclaimed that the earth moved. They were not either just wrong or quite wrong. Part of what they meant by 'earth' was fixed position. Their earth, at least, could not be moved. Correspondingly, Copernicus's innovation was not simply to move the earth. Rather it was a whole new way of regarding the problems of physics and astronomy, one that necessarily changed the meaning of both 'earth' and 'motion'. Without those changes the concept of a moving earth was mad."13

So it is only in a sort of 'madness' - by the old standards - that a new paradigm can be conceived. It is not logically constructed, step by step. It is unusual for the new structure of thought to be consciously anticipated or viewed in advance:

"Instead, the new paradigm, or a sufficient hint to permit later articulation, emerges all at once, sometimes in the middle of the night, in the mind of a man deeply immersed in crisis. What the nature of that final stage is - how an individual invents (or finds he has invented) a new way of giving order to data now all assembled - must here remain inscrutable and may be permanently so.

"Let us here note only one thing about it. Almost always the men who achieve these fundamental inventions of a new paradigm have been either very young or very new to the field whose paradigm they change. And perhaps that point need not have been made explicit, for obviously these are the men who, being little committed by prior practice to the traditional rules of normal science, are particularly likely to see that those rules no longer define a playable game and to conceive another set that can replace them."14

In other words, even on the level of individuals and personalities, according to Kuhn, the attack on the old paradigm is an external one. Certain individuals or groups from outside the field manage to penetrate it and set about undermining and demolishing the structure around them, using the experience and the materials gained in doing so to build a more stable structure on new foundations in its place. The development is not a gradual or evolutionary one; the 'revolutionaries' possess, right from the beginning, a firm conviction of the necessity of what they are doing and a firm plan - however intuitive or embryonic - of the essentials of the structure they are about to build.

And they themselves have been converted not gradually, "but by a relatively sudden and unstructured event like the gestalt switch. Scientists then often speak of 'scales falling from the eyes' or of the 'lightning flash' that 'inundates' a previously obscure puzzle, enabling its components to be seen in a new way that for the first time permits its solution".15

The same applies to the gradual conquest, by the revolutionaries, of the scientific field. Before the scientists can talk to each other again, every scientist in the old camp who is capable of it must undergo the same 'sudden' conversion as that experienced by the revolutionaries themselves:

"... before they can hope to communicate fully, one group or the other must experience the conversion that we have been calling a paradigm shift. Just because it is a transition between incommensurables, the transition cannot be made a step at a time, forced by logic and neutral experience. Like the gestalt switch, it must occur all at once (though not necessarily in an instant) or not at all."16

In this, as in all other respects, scientific development is dialectical and revolutionary to the core.


Kuhn correctly sees all human knowledge as socially constructed. To work within a branch of science, he points out, is to help reproduce and define the identity of a particular community - the community of specialists concerned.

In addition to the obvious practical tests of a scientific theory, there is also an internal test. It is this: how much consensus can the theory generate? A theory which can get only this or that sectional interest to mobilise behind it is not likely to be as influential in the long run as one which can cut across sectional interests, building a community of truly universal scope.

Marx and Engels were interested in assembling the big picture - uniting the natural and social sciences to form a single science. Theirs was a revolutionary new scientific paradigm which failed only in the sense that its natural constituency - the working class - was materially defeated on each occasion when it attempted to bring freedom and reason to the world.

Today, rampant and unrestrained capitalism threatens not only freedom and reason, but the very existence of a habitable planet. Meanwhile scientists aware of the dangers of climate change are struggling against heavy odds to defend their intellectual autonomy, threatened as this is by corporate interests bent on concealing and distorting the facts.

In a world currently dominated by grotesquely wealthy state terrorists politically in league with religious fundamentalists, humanity needs autonomous, free-thinking, self-organised science as never in history before. Our survival as a species depends on it. Across the world, scientists - and that includes all of us - must get politically active precisely in order to defend the autonomy of science. For the scientific community to link up and overcome its internal divisions, it must realise where the true source of disagreement lies.

In climate research, for example, it is only 'scientists' in the pay of Exxon-Mobil and the other oil corporations (building on techniques developed previously by the tobacco companies) who make it appear that there are 'two sides' on the issues which matter. There are not two sides. Instead, there is science on the one hand; corruption and irrationality on the other. Following the inspiring example of the vast majority of climate science researchers, scientists across the globe may be beginning to switch sides, learning to speak out against the very corporate interests which stifle 'inconvenient truths', yet which unfortunately provide the bulk of scientific funding.

In order to find the necessary moral courage and social support, this international community will have no choice but to view itself for the first time as inseparable from the only truly internationalist, truly incorruptible, truly revolutionary political alternative to market insanity and the corporations. It will to an increasing extent view itself as inseparable from our class. And I mean all of ours.

A Communist Party which did not represent this intellectual and social force would not be worthy of the name.