The Structure of Scientific Revolutions
Chris Knight. Unpublished typescript, c.1982
‘Science’, according to Leon Trotsky, ‘is knowledge that endows us with power.’ In the natural sciences, the search has been for power over natural forces and processes. Astronomy made possible the earliest calendars, predictions of eclipses, accurate marine navigation. The development of medical science permitted an increasing freedom from and conquest of disease. The modern advances of physics, chemistry and the other natural sciences have today given us an immense power to harness natural forces of all kinds and have utterly transformed the world in which we live.
Potentially at least, the resulting empowerment is that of our whole species. Science is the self-knowledge and power of humanity at this stage of our evolution on this planet — and not merely the political power of one group of human beings over others. From the standpoint of Marxism, it is this intrinsic internationalism of science — the global, species-wide nature of the human power it represents — which is its strength, and which distinguishes science from mere local, national, territorial or class‑based (i.e. religious, political etc.) forms of consciousness. Ideologies express only the power of certain sections of society; science belongs to the human species as such.
Social research, however, has been a search for power and freedom in a different sense. It has always been a question of particular classes or sectional interests which have sought the freedom to exploit or to constrain the behaviour of other human beings. In other words, the search for power in the social sciences has always been political. Even the development of natural science itself — although intrinsically international and of value to the species as a whole — has necessarily taken place within this limited and limiting social context. It has always been torn between two conflicting demands — between the long‑term requirements of the human species as such on the one hand, and the immediate requirements of particular social classes or sectional interests in opposition to wider needs on the other.
Political power and species‑power — these are the two poles between which science has always oscillated. Between these two extremes, the various forms of knowledge have formed a continuum. At one end have been the sciences least directly concerned with social issues — mathematics, for example — while at the other have been fields such as history, politics and (relatively recently) sociology — fields whose social implications have been immediate and direct. The more direct the social implications of each field, the more direct and inescapable have been the political pressures upon it. And wherever political pressures have prevailed, knowledge has been distorted and blown off course. Instead of expressing the power of the human species generally, it has expressed only the conflict ing powers of various social groups. Among the social sciences, the case of social anthropology affords a particularly clear example. It is probably true to say that twentieth century social anthro pology has contributed not one iota to the power of the human species generally, however much it may have proved useful to Europeans interested in understanding and thereby facilitating the mastery of the “primitive” cultures of the world.
From this standpoint, social anthropology may seem to differ little from other forms of political ideology. It is not “pure” science. It may be rooted at one end in objective reality — in the “traditional” cultures which anthropologists have described. But, at the other end, it has always been rooted in the evolving requirements of one particular section of humanity in opposition to others. “Anthropology”, to put it bluntly, is the child of colonialism and imperialism — forces which have directly served the needs only of a minute fraction of the human race as a whole.
It is the narrowness and contradictory nature of the interests served which accounts for the distortions which anthropological knowledge has suffered. An anthropology which was a genuine “science of humankind” — an anthropology which was genuinely rooted not only in the needs of the peoples under study but also in the needs of the human species as a whole — would be very different. Such a form of knowledge would differ from natural science in being about people rather than objects — in being concerned with ourselves, not just “nature” conceived as outside ourselves. But it would be similar to natural science in the sense that it would be genuinely universal and in that sense “objective” — an expression of the self-knowledge of the human species as such.
Social conditions of scientific objectivity
The ideological characteristics of twentieth century anthropological theory have been well documented. But what of the Marxism against which so much of this ideology was for so long directed? Was not Marx’s work equally ideological?
In an intense polemical attack upon Marxism, Karl Wittfogel — author of Oriental Despotism — concedes that Marx was in principle firmly committed to the independence and autonomy of science. Soviet authorities, he writes, always cited Lenin’s concept of “par tisanship” (partiinost) to justify “bending” science — even to the point of falsifying data — in order to render it more suitable for political use. This idea of “utility” or “manipulation” seemed to follow naturally, according to Wittfogel, from Marx’s initial premise that all knowledge was socially conditioned — produced by social classes only to suit their economic and political needs. To the Soviet authorities, scientific truth was always something to be manipulated for political ends. But Wittfogel continues:
“Marx, however, did not hold this view. He not only empha sized that a member of a given class might espouse ideas that were disadvantageous to his class — this is not denied by Lenin and his followers — but he also demanded that a genuine scholar be oriented toward the interests of mankind as a whole and seek the truth in accordance with the immanent needs of science, no matter how this affected the fate of any particular class, capitalists, landowners or workers. Marx praised Ricardo for taking this attitude, which he called “not only scientifically honest but scientifically required.” For the same reason, he condemned as “mean” a person who subor dinated scientific objectivity to extraneous purposes: “…a man who tries to accommodate science to a standpoint which is not derived from its own interests, however erroneous, but from outside, alien, and extraneous interests, I call ‘mean’ (gemein)”.
Marx was entirely consistent when he called the refusal to accommodate science to the interests of any class — the workers included — “stoic, objective, scientific.” And he was equally consistent when he branded the reverse behaviour a “sin against science”.
These are strong words. They show Marx determined to maintain the proud tradition which characterized independent scholarship throughout the ages. True, the author of Das Capital did not always — and particularly not in his political writings — live up to his scientific standards. His attitude, nevertheless, remains extremely significant. The camp followers of “partisan” science can hardly be blamed for disregarding principles of scientific objectivity which they do not profess. But Marx, who accepted these principles without reservation, may be legitimately criticised for violating them’.
Karl Marx, writes Wittfogel, played two mutually incompatible roles. He was a great scientist, but he was also a political revolutionary. He championed — as every scientist must do — ‘the interests of mankind as a whole’, but he also championed the interests of the international working class. The self-evident incompatibility (as Wittfogel sees it) of these two activities meant that ‘Marx’s own theories…are, at decisive points, affected by what he himself called “extraneous interests”’.
Wittfogel is cited by the social anthropologist Marvin Harris, whose views on this issue appear to be quite similar. Harris counterposes Marxism’s “scientific” component against its “dialectical and revolutionary” aspect, his aim being to render the former serviceable by decontaminating it of all traces of the latter. According to Harris, “Marx himself took pains to elevate scientific responsibility over class interests.” But this was only in his scientific work. Much of Marx’s work was political, and here, science was subordinated to political ends — and therefore misused. According to Harris, if science is championed for political reasons, this must lead to the betrayal of science’s own objectivity and aims:
“If the point is to change the world, rather than to interpret it, the Marxist sociologist ought not to hesitate to falsify data in order to make it more useful.”
Wittfogel’s point that Marx tried to base his science on “the interests of mankind as a whole” is a valuable one. We may also agree with Harris that Marx “took pains to elevate scientific responsibility over class interests” — if by “class interests” are meant interests of a purely sectional, limited, narrowly local or national kind. But the difficulty is precisely here. Like Einstein, and like all great scientists down through the ages, Marx believed that it was his responsibility as a scientist to place before all sectional interests the general interests of humanity. The question he faced is the one which still faces us today: in what concrete form, in the modern world, are these general interests expressed?
Marx came to the conclusion, on the basis of his scientific studies, that the general interests of humanity were not represented by the various ruling classes of nineteenth century Europe. These interests conflicted not only with one another but also with those of the human species as such. They could not, therefore, form the social basis for a genuinely objective social science.
The weakness in the position of both Wittfogel and Harris is that they have nothing to say on this issue. They are in the peculiar position of both agreeing with Marx’s basic premises and yet refusing even to discuss the possibility that his conclusions might have been correct. They fully agree that science must base itself upon general human interests. Marx, basing himself on this idea, reached the conclusions (a) that science was itself politically revolutionary to the extent that it was genuinely true to itself and universal, (b) that it was this kind of ‘politics’ (i.e. the politics of science itself) that the modern revolutionary movement required and (c) that the only possible social basis for such a science-inspired politics was the one class in society which was itself a product of science, which was already as intrinsically international as scientific development and whose interests countered all existing sectional interests. But neither Wittfogel nor Harris mount any argument on all this. They simply take it as self-evident that the interests of humankind are one thing whereas working class interests are another.
Karl Marx knew — and every Marxist worthy of the name knows — that it is not worth committing oneself to a social force unless it genuinely does represent by its own very existence the wider interests of humanity. And every Marxist worthy of the name knows that it is only real science — the real discoveries of scientists working independently and for science’s own autonomous ends — which can be utilised by humanity as a means to self-enlightenment and emancipation. From this standpoint we can see the absurdity of Harris’ argument that if the point is to change the world, the Marxist sociologist ‘ought not to hesitate to falsify data in order to make it more useful’. How can ‘falsified data’ conceivably be of value to humankind? How can it be useful to anyone interested in changing the world?
Harris is right to insist that when a sectional political interest — be it ‘Marxist’ or not — takes hold of scientific work, science itself will suffer. A particular, national and therefore limited political party or a particular group ruling a particular state (as, for example, the Soviet bureaucracy and ‘Communist’ apparatus during the ‘cold war’) may well feel itself to have particular interests of its own, which it sets above the wider interests which it claims to represent. In that case, to the extent that scientists are involved, science will certainly be distorted. But a distortion of science (i.e. its partial transformation into ideology) can only involve a limitation of its long‑term ultimate appeal and of its human usefulness. Wherever such things happen, therefore, the particular group concerned reduces rather than enhances its power to ‘change the world.’
All distortions, falsifications or mystifications express the power only of sectional social interests in opposition to wider ones. Marx at no time advocated tailoring science to suit the felt needs of this, that, or the other sectional interest — whether working class or not:
“It is not a matter of knowing what this or that proletarian, or even the proletariat as a whole, conceives as its aims at any particular moment. It is a question of knowing what the proletariat is, and what it must historically accomplish in accordance with its nature”.
For Marx, to know “what the proletariat is” constituted a scientific question, which could only be given a scientific answer in complete independence of any immediate political pressures or concerns. Far from arguing for the subordination of science to politics, Marx insisted on the subordination of politics to science.
Engels wrote: “….the more ruthlessly and disinterestedly science proceeds the more it finds itself in harmony with the interests of the workers.” We can be confident that this accurately expressed Marx’s own views. Science, as humanity’s only universal, international, species‑unifying form of knowledge, had to come first. If it had to be rooted in the interests of the working class, this was only in the sense that all science has to be rooted in the interests of the human species as a whole, the international working class embodying these interests in the modern epoch (just as the requirements of production have always embodied these interests in previous periods). There was no question here of any subordination to sectional needs. In being placed first, science cut across sectional divisions and became the medium of expression for a new form of political consciousness. In this sense, it even created “the international working class” itself. Without science, there were only sectional working class political movements; only through scientific analysis could the general interests be laid bare. While “science”, for Marx, was not an abstraction with power of its own — it could not descend as if from the skies and intervene in history or in political life — this did not detract from its significance. Admittedly, science — as itself a social product — could not add anything to the strength of the working class which was not already there. It could not impose itself upon the workers’ movement as if from outside. It was in and through science alone that workers internationally could become aware of the global, species wide, strength which was already theirs. And it was only in becoming aware of its own power that the “international working class” could politically exist. There was no question, therefore, of science being subordinated to a pre existing political force. The political force was science’s own and could not exist without it. The previously‑prevailing relationships between science and politics were reversed.
For Marx, social science — including his own — was as much a product of class relationships as any other form of social consciousness. His general formulation is well‑known:
“the ideas of the ruling class are, in every age, the ruling ideas: i.e. the class which is the dominant material force in society is at the same time its dominant intellectual force. The class which has the means of material action at its disposal, has control at the same time over the means of mental production, so that in consequence the ideas of those who lack the means of mental production are, in general, subject to it. The dominant ideas are nothing more than the ideal expression of the dominant material relationships, the dominant relationships grasped as ideas, and thus of the relationships which make one class the ruling one; they are consequently the ideas of its dominance”.
For this reason, Marx did not consider it to be possible to change the prevailing ideas of society — or to produce a universally‑agreed science of society — without breaking the material power of those forces which distorted science. It was because Marx saw social contradictions as the source of mythological and ideological contradictions that he was able to insist that only the removal of the social contradictions themselves could remove their expressions in ideology and science. This is what Marx meant when he wrote:
“All social life is essentially practical. All the mysteries which lead theory towards mysticism find their rational solution in human practice and in the comprehension of this practice”.
“The resolution of theoretical contradictions is possible only through practical means, only through the practical energy of man. Their resolution is by no means, therefore, the task only of the understanding, but is a real task of life, a task which philosophy was unable to accomplish precisely because it saw there a purely theoretical problem.”
So from the standpoint of Marx and Engels it was in order to remain true to the interests of science — to solve its internal theoretical contradictions — that they felt obliged, as scientists, (a) to identify with a material social force which could remove the ‘extraneous interests’ distorting the objectivity of science and (b) to take up the leadership of this material force themselves. Their idea was not that science is inadequate, and that politics must be added to it. Their idea was that science — when true to itself — is itself revolutionary, and that it must recognize no other “politics” but its own.
Marx and Engels believed science could acquire this unprecedented political autonomy for a social reason: there had come into existence within society for the first time — and as a direct result of scientific development itself — a “class” which was not really a class at all, which had no traditional status or vested interests to protect, no power to dispense patronage, no power to divide man from man and therefore no power to distort science in any way. “Here”, wrote Engels of the working class, “there is no concern for careers, for profit‑making, or for gracious patronage from above.” Only here could science be true to itself, for only here was a social force of a truly universal kind, capable of uniting the species as a whole. This was the condition for a truly independent, truly autonomous, truly universal science of humankind — the existence of:
“…a class in civil society which is not a class of civil society, a class which is the dissolution of all classes, a sphere of society which has a universal character because its sufferings are universal, and which does not claim a particular redress because the wrong which is done to it is not a political wrong but wrong in general. There must be formed a sphere of society which claims no traditional status but only a human status, a sphere which is not opposed to particular consequences but is totally opposed to the assumptions of the….political system, a sphere finally which cannot emancipate itself without emancipating itself from all other spheres of society, without therefore emancipating all these other spheres, which is, in short, a total loss of humanity and which can only redeem itself by a total redemp tion of humanity.
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Much of the preceding argument may itself seem tendentious. Almost any political or social philosopher will claim, after all, that his or her theory expresses general human interests rather than narrow sectional ones. To use “fidelity to the interests of humanity” as a yardstick by which to measure the scientific value of a conceptual system is therefore not possible — unless some objective test for this fidelity or correspondence can be found. But what kind of test could this possibly be?
In the long term, no doubt, the test for any hypothesis in the natural sciences is workability. Is the idea useful to the specialists concerned? Does it lessen their mental effort in solving problems? In other words, does the hypothesis add to the power — be it purely intellectual or practical as well — of scientists in the relevant field?
If it does, then they should ultimately come to recognize the fact. Assuming efficiency to be their criterion (and they will not be scientists otherwise), support for the theory will spread. Internal coherence (agreement between the theory’s parts) will find expression in widespread social agreement. Such a capacity to produce agreement is the ultimate social test of science.
In the long term, for Marxism or for social science, a similar test must be undergone. Science differs from mere ad hoc knowledge, technique or common sense by virtue of its abstract, symbolic, formal characteristics. Science is a symbolic system. Like any such system, its meaning depends on agreement. The figure “2” means “two” only because we all say it does. It could equally well mean “nine.” All symbolic systems — including myths and ideologies — depend in this sense upon social agreement. But, in the case of myths and ideologies, the scope of agreement extends only so far. A point is reached at which disagreement arises — a disagreement rooted in social contradictions. And when this happens, the need to reconcile incompatible meanings leads to contradictions of an internal kind — within the symbolic system itself.
Mythology and ideology are expressions of social division. This is the essential feature which distinguishes these forms of knowledge from science. Science expresses the power and the unity of the human species — a power which, in class‑divided societies, human beings have increasingly possessed in relation to nature even though not in relation to their own social world. A science of society, in order to prove itself as science, would have to prove that it was without internal contradictions, and that it was consistent with natural science and with science as a whole. In the long term, it could only prove this practically. It would have to demonstrate its internal consistency by demon strating its roots in social agreement of a kind uniting the human race. It would have to demonstrate in practice, in other words, that it formed part of a symbolic system — a global “language” woven out of the concepts of science — which was capable in practice of embracing and ultimately politically unifying the globe.
Yet this is not the only test. In the case of every scientific advance, the first test is theoretical. Copernicus knew that the earth moved. And he knew it long before this fact had been proven to the satisfaction of others and universally agreed. Einstein knew that light was subject to gravitational laws. And he knew this long before it was demonstrated in 1919 during an eclipse watched from observatories in Cambridge and Greenwich (when it was shown that light-rays from a star were deflected by the gravitational pull of the sun). In scientific discovery it has always been the same. A scientific revolution is validated on the level of pure theory long before passing the final test of practice.
The only ultimate validation of Marxism as science would be the demonstration of its power to produce agreement on a global scale — its power to unify humanity. But if Marxism is genuine science, it ought to be possible to demonstrate this potential in purely theoretical terms in advance. The question arises: How?
The structure of scientific revolutions
One of the most important books to have appeared in recent years is T. S. Kuhn’s The Structure of Scientific Revolutions. It would be difficult to overestimate the impact which this work has had on the sociology and philosophy of science.
Kuhn does not discuss the relationship between scientific development and social and 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 other conceptual systems. 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 rival systems of knowledge cannot. 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.
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 scientist 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 nornally fails to evoke the controversies over fundanentals that today often seem endemic among, say, psychologists or sociologists.”
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 conmon 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 illegitinate techniques of persuasion or even to 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 nornal 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 comunity could form. And they, too — like the social sciences today — were divided by disagreements over fundanentals: disagreenents 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 around the sun. In these 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 to belong only to the far distant past, it may be remembered that Charles Darwin and his supporters only a century ago were considered to be putting forward a theologically dangerous and politically subver sive theory when they argued that the human anatomy had evolved fron that of an ancestral ape like being. 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 fron the realm of political controversy. But conversely, it is only once its initial political colouration has faded away that science produces sufficient general agreement for it to be generally recognised as science. 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 recognized scientific achievements that for a time provide model problems and solutions to a community of practitioners”. Such achievements are products of scientific revolutions. A scientific revolution is not simply an addition to pre‑existing knowledge. It is, within any given field, “a reconstruction of the field from new funda mentals….” 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 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 revol utions 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 favor 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 polarization 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 differerences, 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 extrapolitical or extrainstitutional event.”
It is just the same, writes, Kuhn, when, in the course of a scientific revolution, scientists polarize 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’‑i.e. 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’ procedure and what does not, or what constitutes ‘rational’ behaviour and what does not. Disputes within the framework of a paradigm can be settled in an orderly way, on the basis of the rules laid down by the paradigm itself. This is what ‘normal science’ is all about. But when an entire paradigm is being challenged by another one, there is no ‘purely logical’ way to proceed. The supporters of the new paradigm may feel that their own franmwork is far more powerful, far simpler, more elegant and more logical than the old framework of their opponents. But they cannot convince their opponents of this on the basis of their opponents’ own rules. If the supporters of the old paradigm are to be won over, they must make a ‘leap’ which involves abandoning their former conceptions as to what constituted ‘logic’ and what did not:
“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 nornal 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 defense 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 immensley 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 probabil istically 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.”
Anomaly and normal science
It is not until a paradigm has been generally accepted that ‘scientific research’ in the normal sense can get under way. 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?”
Once — following a scientific revolution — a paradigm has become accepted, a period of conservatism sets in. This is a period of “mopping-up operations” — 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.
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 problem atic to be worth the time.” 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 extrenely 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 or logical way. All the problems which today form the subject matter of nuclear physics would — in Descartes’s time- have been irrelevant, illegitimate, metaphysical and unscientific even to discuss. And, of course, none of these problems was discussed or was even seen as a problem at all. It was “known” what the universe was composed of — it was composed not of curved space‑time, nor of electromagnetic fields but of very small, hard objects which collided with one another according to mechanical laws.
However,it is not for us simply to condenm 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 easy‑going, open‑minded conmunity 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. Kuhn explains:
“In the development of any science, the first received paradigm is usually felt to account quite successfully for most of the observations and experiments easily accessible to that science’s practitioners. Further development, therefore, ordinarily calls for the construction of elaborate equipment, the development of an esoteric vocabulary and skills, and a refinenent of concepts that increasingly lessons their resemblances to their usual common‑sense prototypes. That professionalization leads on the one hand, to an immense restriction of the scientists’ vision and to a considerable resistance to paradigm change. The science has become increasingly rigid. On the other hand, within those areas to which the paradigm directs the attention of the group, normal science leads to a detail of information and to a precision of the observation‑theory match that could be achieved in no other way. Furthermore, that detail and precision‑of‑match have a value that transcends their not always very high intrinsic interest. 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 recognize 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 anonalies that lead to paradigm change will penetrate existing knowledge to the core.”
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 of normal science behaves in a wholly unexpected way. To normal science, such anomlies are merely an irritation or a nuisance. In attepts 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 paradign 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 fundmnentally 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.” “With them”, 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.” 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 comunication 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.” All these are signs that the old theor etical edifice is crumbling and that a new one is about to take its place.
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’ 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.”
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 fundanental 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.”
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 the ‘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”.
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”.
In this as in all other respects, scientific development is dialectical and revolutionary to the core.
 “An individual scientist may not at all be concerned with the practical applications of his research. The wider his scope, the bolder his flight, the greater his freedom in his mental operations from practical daily necessity, the better. But science is not a function of individual scientists; it is a social function. The social evaluation of science, its historical evaluation is determined by its capacity to increase man’s power to foresee events and master nature.” L. D. Trotsky, “Dialectical Materialism and Science.” In: Isaac Deutscher (ed.) The Age of Permanent Revolution: A Trotsky Anthology. Dell, New York, 1964, p. 344.
 C. Knight, Blood Relations: Menstruation and the origins of culture. New Haven and London: Yale University Press, 1991, pp. 50-70.
 K. Wittfogel, “The Ruling Bureaucracy of Oriental Despotism: A Phenomenon that Paralysed Marx.” The Review of Politics, 15 (1953): 350-59; pp. 355-56. Wittfogel cites Marx, Theorien über den Mehrwert. Aus dem nachgelaaenen Manuskript “Zur Kritik der Politischen Oekonomie”; published by K. Kautsky. 3 vols. 1921, II, 1: 310-313.
 Ibid., p. 356n.
. The Rise of Anthropological Theory. Routledge, London 1969.
 Ibid., pp. 4-5; 220-221.
 K. Marx and F. Engels, “The Holy Family” (1845). In T. B. Bottomore and M. Rubel (eds), Karl Marx: Selected Writings in Sociology and Social Philosophy. Penguin, Harmondsworth, 1963, p. 84.
 As long as the working class is weak, wrote Marx, the theoreticians aiming to help it “improvise systems and pursue a regenerative science.” But once the working class is strong, its theoreticians “have no further need to look for a science in their own minds; they have only to observe what is happening before their eyes and to make themselves its vehicle of expression… from this moment, the science produced by the historical movement, and which consciously associates itself with this movement, has ceased to be doctrinaire and has become revolutionary”. “The Poverty of Philosophy” (1847). In: Bottomore and Rubel (eds), op. cit., p. 81.
10. As Trotsky puts it: “…the consciousness of strength is the most important element of actual strength.” L. D. Trotsky, Whither France? Merit Publishers, New York, 1968, p. 116. Marx had the same idea in mind when he wrote: “…we must force these petrified relationships to dance by playing their own tune to them! So as to give then courage, we must teach the people to be shocked by themselves.” “Towards a Critique of Hegel’s Philosophy of Right. Introduction” (1843‑4). In D. McLellan (ed.), Karl Marx: Early Texts. Blackwell, Oxford, 1972, p. 118.
 “The German Ideology” (1845‑6). In: Bottomore and Rubel (eds.), op. cit., p. 93.
 “Theses on Feuerbach” (1845). Thesis VIII. In Bottomore and Rubel (eds.), op. cit., p. 84.
“The Economic and Philosophic Manuscripts” (1844). In: ibid. p. 87.
 Actually, Marx had a very low opinion of “political thought” in general precisely because of its inevitably subjective, unscientific, bias: “Political intelligence is political just because it thinks inside the limits of politics. The sharper and livelier it is the less capable it is of comprehending social evils…. the principle of politics is the will. The more one‑sided, and thus the more perfect political intelli gence is, the more it believes in the omnipotence of the will, and thus the more incapable it is of discovering the sources of social evils.” The King of Prussian and Social Reform (1844). In: McLellan (ed.), op. cit., p. 214. If Marx believed in the necessity for political struggle, it was because he understood the political nature of the obstacles to human emancipation and to the autonomy of science. It was not because of anything intrinsically political about this emancipation or its science. Socialism when realised is not political: “Revolution in general – the overthrow of the existing power and dissolution of previous relationships – is a political act. Socialism cannot be realized without a revolution. But when its organizing activity begins, when its peculiar aims, its soul comes forward, then socialism casts aside its political cloak” – ibid., p. 221.
 F. Engels, Ludwig Feuerbach and the End of Classical German Philosophy.” In: K. Marx and F. Engels, On Religion. Moscow, 1957, p. 266.
 K. Marx, “Towards a Critique of Hegel’s Philosophy of Right”, (1833‑43). In. Bottomore and Rubel (eds.), op. cit., p. 190.
 T. S. Kuhn “The Structure of Scientific Revolutions”. Inter national Encyclopaedia of Unified Science. Volume 2, Number 2. Second edition enlarged. University of Chicago Press, Chicago, 1970, p. viii. Marx probably derived this idea at least in part from Feuerbach, although it is also a powerful theme in Hegel’s writings. Feuerbach writes:
“That is true in which another agrees with me – agreement is the first criterion of truth; but only because the species is the ultimate measure of truth. That which I think only according to the standard of my individuality is not binding on another, it can be conceived otherwise, it is an accidental, merely subjective, view. But that which I think according to the standard of the species, I think as man in general only can think, and consequently as every individual must think if he thinks normally… That is true which agrees with the nature of the species, that is false which contradicts it. There is no other rule of truth.”
Ludwig Feuerbach, Sämtliche Werke. Vols. 1-12/13 (13 vols. in 12). Stuttgart‑Bad Canstatt, Fromann Verlag Günther Holzboog, 1960‑64. Vol.‑6, p. 191 (“The Essence of Christianity”). In E. Kamenka, The Philosophy of Ludwig Feuerbach. Routledge, London, 1970, pp. 101‑02.
 For this idea as it was expressed during the Russian Revolution see C. D. Knight, “Past, Future and the Problem of Communication in the work of V. V. Khlebnikov”. Unpublished M. Phil. thesis (1976) Brighton: University of Sussex.
 T. S. Kuhn, “The Structure of Scientific Revolutions. Inter national Encyclopaedia of Unified Science. Volume 2, Number 2. Second edition enlarged. University of Chicago Press, Chicago, 1970.
 Ibid., p. viii.
 Loc. cit.
 Op. cit., p, 85.
 Ibid., pp. 93-4.
 Ibid., p. 94
 Ibid., pp. 4-5.
 Ibid, p. 24.
 Ibid., p. 37. Kuhn adds: “It is no criterion of goodness in puzzle that its outcome be intrinsically interesting or important. On the contrary, the really pressing problems, e.g. a cure for cancer or the design of a lasting peace, are often not puzzles at all, largely because they may not have a solution… A paradigm can, for that matter, even insulate the community from those socially important problems that are not reducible to the puzzle form, because they cannot be stated in terms of the conceptual and instrumental tools the paradigm supplies”. Loc. cit. Once a paradigm has been accepted by a scientific community, the problems which it cannot solve are felt to be illegitimate or “unscientific”. Anyone who then insists on the importance of these problems is excluded from the scientific community and considered eccentric or even mad.
 Ibid., pp. 64-5.
 Ibid., p. 83.
 Ibid., p. 91.
Ibid., pp. 149-50.
 Ibid., pp. 89-90.
 Ibid., p. 122.
 Ibid., p. 150.