Historians Of Science

"To introduce my story, I take the reader back to 1962, when the academic world saw the publication of The Structure of Scientific Revolution, by Thomas Kuhn. … Most certainly, it upset my own Logical Empiricist assumptions. It had that effect for two reasons. The first was his claim, vividly documented, that past scientific revolutions were not the unambiguous expression of sheerly logical and experimental factors, rationally played out according to a well-defined methodology. Rather, they were the expression of a variety of nonlogical factors as well: social, psychological, metaphysical, technological, aesthetic, and personal. … The second reason for the ensuing controversy was his claim, also well-documented, that the unit of scientific understanding is not the sentence, or set of sentences, but rather the so-called "paradigm", or family of paradigms."

"Thomas Kuhn was undoubtedly the strongest influence on the philosophy of science in the last third of the twentieth century. Yet today, at the beginning of the twenty-first century it is unclear what his legacy really is. In the philosophy of science there is no characteristically Kuhnian school. This could be because we are all Kuhnians now. But it might also be because Kuhn's thought, although revolutionary in its time, has since been superseded. In a sense both may be true."

"Kuhn’s treatment of philosophical ideas is neither systematic nor rigorous. He rarely engaged in the stock-in-trade of modern philosophers, the careful and precise analysis of the details of other philosophers’ views, and when he did so the results were not encouraging."

"By now it may be clear that the position I'm developing is a sort of post-Darwinian Kantianism."

"I rapidly discovered that Aristotle had known almost no mechanics at all. ... How could his characteristic talents have deserted him so systematically when he turned to the study of motion and mechanics? Equally, if his talents had so deserted him, why had his writings in physics been taken so seriously for so many centuries after his death? ... I was sitting at my desk with the text of Aristotle's Physics open in front of me... Suddenly the fragments in my head sorted themselves out in a new way, and fell into place together. My jaw dropped, for all at once Aristotle seemed a very good physicist indeed, but of a sort I'd never dreamed possible. Now I could understand why he had said what he'd said, and what his authority had been. Statements that had previously seemed egregious mistakes, now seemed at worst near misses within a powerful and generally successful tradition. That sort of experience -- the pieces suddenly sorting themselves out and coming together in a new way -- is the first general characteristic of revolutionary change that I shall be singling out after further consideration of examples. Though scientific revolutions leave much piecemeal mopping up to do, the central change cannot be experienced piecemenal, one step at a time. Instead, it involves some relatively sudden and unstructured transformation in which some part of the flux of experience sorts itself out differently and displays patterns that were not visible before."

"A scientific theory is usually felt to be better than its predecessors not only in the sense that it is a better instrument for discovering and solving puzzles but also because it is somehow a better representation of what nature is really like. One often hears that successive theories grow ever closer to, or approximate more and more closely to, the truth. Apparently generalizations like that refer not to the puzzle-solutions and the concrete predictions derived from a theory but rather to its ontology, to the match, that is, between the entities with which the theory populates nature and what is “really there.” Perhaps there is some other way of salvaging the notion of ‘truth’ for application to whole theories, but this one will not do. There is, I think, no theory-independent way to reconstruct phrases like ‘really there’; the notion of a match between the ontology of a theory and its “real” counterpart in nature now seems to me illusive in principle. Besides, as a historian, I am impressed with the implausability of the view. I do not doubt, for example, that Newton’s mechanics improves on Aristotle’s and that Einstein’s improves on Newton’s as instruments for puzzle-solving. But I can see in their succession no coherent direction of ontological development. On the contrary, in some important respects, though by no means in all, Einstein’s general theory of relativity is closer to Aristotle’s than either of them is to Newton’s."

"We may, to be more precise, have to relinquish the notion, explicit or implicit, that changes of paradigm carry scientists and those who learn from them closer and closer to the truth"

"These examples point to the third and most fundamental aspect of the incommensurability of competing paradigms. In a sense that I am unable to explicate further, the proponents of competing paradigms practice their trades in different worlds. One contains constrained bodies that fall slowly, the other pendulums that repeat their motions again and again. In one, solutions are compounds, in the other mixtures. One is embedded in a flat, the other in a curved, matrix of space. Practicing in different worlds, the two groups of scientists see different things when they look from the same point in the same direction. Again, that is not to say that they can see anything they please. Both are looking at the world, and what they look at has not changed. But in some areas they see different things, and they see them in different relations one to the other. That is why a law that cannot even be demonstrated to one group of scientists may occasionally seem intuitively obvious to another."

"The subject of a gestalt demonstration knows that his perception has shifted because he can make it shift back and forth repeatedly while he holds the same book or piece of paper in his hands. Aware that nothing in his environment has changed, he directs his attention increasingly not to the figure (duck or rabbit) but to the lines of the paper he is looking at. Ultimately he may even learn to see those lines without seeing either of the figures, and he may then say (what he could not legitimately have said earlier) that it is these lines that he really sees but that he sees them alternately as a duck and as a rabbit. ...As in all similar psychological experiments, the effectiveness of the demonstration depends upon its being analyzable in this way. Unless there were an external standard with respect to which a switch of vision could be demonstrated, no conclusion about alternate perceptual possibilities could be drawn."

"Scientific revolutions are inaugurated by a growing sense... that an existing paradigm has ceased to function adequately in the exploration of an aspect of nature to which that paradigm itself had previously led the way."

"Philosophers of science have repeatedly demonstrated that more than one theoretical construction can always be placed upon a given collection of data. History of science indicates that, particularly in the early developmental stages of a new paradigm, it is not even very difficult to invent such alternates. But that invention of alternates is just what scientists seldom undertake except during the pre-paradigm stage of their science’s development and at very special occasions during its subsequent evolution. So long as the tools a paradigm supplies continue to prove capable of solving the problems it defines, science moves fastest and penetrates most deeply through confident employment of those tools. The reason is clear. As in manufacture so in science—retooling is an extravagance to be reserved for the occasion that demands it. The significance of crises is the indication they provide that an occasion for retooling has arrived."

"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 refinement of concepts that increasingly lessens their resemblance to their usual common-sense prototypes. That professionalization leads, on the one hand, to an immense restriction of the scientist’s 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."

"In science, as in the playing card experiment, novelty emerges only with difficulty, manifested by resistance, against a background provided by expectation."

"We must now ask how changes of this sort can come about, considering first discoveries, or novelties of fact, and then inventions, or novelties of theory. That distinction between discovery and invention or between fact and theory will, however, immediately prove to be exceedingly artificial."

"Normal science, the puzzle-solving activity we have just examined, is a highly cumulative enterprise, eminently successful in its aim, the steady extension of the scope and precision of scientific knowledge. In all these respects it fits with great precision the most usual image of scientific work. Yet one standard product of the scientific enterprise is missing. Normal science does not aim at novelties of fact or theory and, when successful, finds none."

"Scientists work from models acquired through education and through subsequent exposure to the literature often without quite knowing or needing to know what characteristics have given these models the status of community paradigms"

"The scientific enterprise as a whole does from time to time prove useful, open up new territory, display order, and test long-accepted belief. Nevertheless, the individual engaged on a normal research problem is almost never doing any one of these things. Once engaged, his motivation is of a rather different sort. What then challenges him is the conviction that, if only he is skillful enough, he will succeed in solving a puzzle that no one before has solved or solved so well."

"These three classes of problems—determination of significant fact, matching of facts with theory, and articulation of theory—exhaust, I think, the literature of normal science, both empirical and theoretical. They do not, of course, quite exhaust the entire literature of science. There are also extraordinary problems, and it may well be their resolution that makes the scientific enterprise as a whole so particularly worthwhile. But extraordinary problems are not to be had for the asking. They emerge only on special occasions prepared by the advance of normal research."

"Few people who are not actually practitioners of a mature science realize how much mop-up work of this sort a paradigm leaves to be done or quite how fascinating such work can prove in the execution."

"Ever since prehistoric antiquity one field of study after another has crossed the divide between what the historian might call its prehistory as a science and its history proper. These transitions to maturity have seldom been so sudden or so unequivocal as my necessarily schematic discussion may have implied. But neither have they been historically gradual, coextensive, that is to say, with the entire development of the fields within which they occurred."

"Men whose research is based on shared paradigms are committed to the same rules and standards for scientific practice. That commitment and the apparent consensus it produces are prerequisites for normal science, i.e., for the genesis and continuation of a particular research tradition."

""Normal science" means research firmly based upon one or more past scientific achievements, achievements that some particular scientific community acknowledges for a time as supplying the foundation for its further practice."

"Normal science, the activity in which most scientists inevitably spend almost all their time, is predicated on the assumption that the scientific community knows what the world is like. Normal science often suppresses fundamental novelties because they are necessarily subversive of its basic commitments."

"Out-of-date theories are not in principle unscientific because they have been discarded. That choice, however, makes it difficult to see scientific development as a process of accretion."

"History, if viewed as a repository for more than anecdote or chronology, could produce a decisive transformation in the image of science by which we are now possessed."

"Somehow, the practice of astronomy, physics, chemistry or biology normally fails to evoke the controversies over fundamentals that today seem endemic among, say, psychologists or sociologists. Attempting to discover the source of that difference led me to recognize the role in scientific research of what I have since called “paradigms.” These I take to be universally recognized scientific achievements that for a time provide model problems and solutions for a community of practitioners."

"To my complete surprise, that exposure to out-of-date scientific theory and practice radically undermined some of my basic conceptions about the nature of science and the reasons for its special success. Those conceptions were ones I had previously drawn partly from scientific training itself and partly from a long-standing avocational interest in the philosophy of science. Somehow, whatever their pedagogic utility and their abstract plausibility, those notions did not at all fit the enterprise that historical study displayed. Yet they were and are fundamental to many discussions of science, and their failures of verisimilitude therefore seemed thoroughly worth pursuing. The result was a drastic shift in my career plans, a shift from physics to history of science and then, gradually, from relatively straightforward historical problems back to the more philosophical concerns that had initially led me to history."

"I suggest that scientific knowledge, though logically more articulate and far more complex, is of this sort. The books and teachers from whom it is acquired present concrete examples together with a multitude of theoretical generalizations. Both are essential carriers of knowledge, and it is therefore Pickwickian to seek a methodological criterion that supposes the scientist can specify in advance whether each imaginable instance fits or would falsify his theory."

"Only when they must choose between competing theories do scientists behave like philosophers."

"If a demarcation criterion exists (we must not, I think, seek a sharp or decisive one), it may lie just in that part of science which Sir Karl ignores."

"The one who contributed most to break down the barrier between physical method and metaphysical method, and to confound their domains, so clearly distinguished in the Aristotelian philosophy, was surely Descartes."

"Agreement with experiment is the sole criteria of truth for a physical theory."

"A physical theory reputed to be satisfactory by the sectarians of one metaphysical school will be rejected by the partisans of another school."

"[U]n symbole n'est, à proprement parler, ni vrai, ni faux; il est plus ou moins bien choisi pour signifier la réalité qu'il représente, il la figure d'une manière plus ou moins précise, plus ou moins détaillée..."

"The first question we should face is: What is the aim of a physical theory? To this question diverse answers have been made, but all of them may be reduced to two main principles: "A physical theory," certain logicians have replied, "has for its object the explanation of a group of laws experimentally established." "A physical theory," other thinkers have said, "is an abstract system whose aim is to summarize and classify logically a group of experimental laws without claiming to explain these laws... Now these two questions — Does there exist a material reality distinct from sensible appearances? and What is the nature of reality? — do not have their source in experimental method, which is acquainted only with sensible appearances and can discover nothing beyond them. The resolution of these questions transcends the methods used by physics; it is the object of metaphysics. Therefore, if the aim of physical theories is to explain experimental laws, theoretical physics is not an autonomous science; it is subordinate to metaphysics... Now, to make physical theories depend on metaphysics is surely not the way to let them enjoy the privilege of universal consent."

"« La Logique peut être patiente, car elle est éternelle. » ("Logic can be patient because it is eternal.") ibid. p. 150"

"There you have, then, a theoretical physics which is neither the theory of a believer nor that of a nonbeliever, but merely and simply a theory of a physicist; admirably suited to classify the laws studied by the experimenter, it is incapable of opposing any assertion whatever of metaphysics or of religious dogma, and is equally incapable of lending effective support to any such assertion."

"Every time people cite a principle of theoretical physics in support of a metaphysical doctrine or physical dogma, they commit a mistake, for they attribute to this principle a meaning not its own, an import not belonging to it."

"He idealized science not just as knowledge but in a political sense too, believing that the management of human affairs could also be more scientific by virtue of being socialist. He was thus particularly inclined to accept the claims of Soviet Marxism to represent science in general, and to accord it the same degree of respect."

"The extent of his faith in science can best be described as religious devotion. He comments himself: 'The same type of mind that would now make a physicist would in the Middle Ages have made a scholastic theologian.'"

"For Bernal the humanistic and the scientific dimensions were one. His vision of the sort of future that science could make possible for mankind was in total contrast to that of Aldous Huxley's Brave New World. Full automation, nuclear energy, and cybernetics could bring a fuller realisation of human potential. His futuristic sketches grew increasingly better grounded as his Marxism matured, making the society of the future set out in The Social Function of Science far more plausible than the one set out in his earlier work, The World, the Flesh and the Devil. His sense of history was sweeping, stretching back into the ancient past and shooting forward into the coming future."

"Never had Frederick Engels' famous notion of 'scientific socialism' been treated so literally."

"[T]radition links us with the revolutionary science of the Renaissance... we can distinguish... four major periods of advance. [1] [C]entred in Italy... the renewal of mechanics, anatomy, and astronomy with Leonardo, Vesalius, and Copernicus, destroying the authority of the Ancients in their central doctrines of man and the world. [2] [S]preading to the Low Countries, France, and Britain, beginning with Bacon, Galileo, and Descartes, and ending in Newton, hammered out a new mathematical mechanical model of the world. [3] [C]entred in industrial Britain and revolutionary Paris, opened... areas of experience... as... electricity... It was then that science could help... with power, machinery, and chemicals, to transform production and transport. [4] [T]he scientific revolution of our own time. ...[T]he beginning of a world science, transforming old and creating new industries, permeating every aspect of human life. ...[N]ow... we find science directly involved in the violent and terrible drama of wars and social revolution."

"The progress in science has been anything but uniform in time and place. ...In the course of time the centres of scientific activity have been continually displaced, usually following rather than leading the migration of the centres of commercial and industrial activity. Babylonia, Egypt, and India have all been the foci of ancient science. Greece became their common heir, and there the rational basis... was first worked out. There was little place for science in Rome and none in the barbarian kingdoms of western Europe. The heritage of Greece returned to the East from whence it had come. In Syria, Persia, and India, even in... China, new breaths... came... in a brilliant synthesis under the banner of Islam. There they underwent a development which... was to give rise to... modern science."

"Science, in one aspect, is ordered technique; in another, it is rationalized mythology. Because it started as a hardly distinguishable aspect of the mystery of the craftsman and the lore of the priest... science was long in establishing any independent existence in society. Even when it did find its own... adepts in medicine, astrology, and alchemy, these formed, for many ages a small group parasitic on wealthy princes, clerics, and merchants. It is only in the last three centuries that science has become traditionally established as a profession in its own right, with its specific education, literature, and fellowship."

"The theme which constantly recurs is the complex interaction between techniques, science, and philosophy. Science stands as a middle term between the established and transmitted practice of men who work for a living, and the pattern of ideas and traditions which assure the continuity of society and the rights and privileges of the classes that make it up."

"[T]he centre of interest... lies in natural science and technology because... the sciences of society were first embodied in tradition and ritual and only took shape under the influence and on the model of the natural sciences."

"[S]cience has so changed its nature over... human history that no definition could be made to fit."

"John Desmond Bernal (1901-1971) was undoubtedly the most important of the "Western" scientists who, during the twentieth century, accepted the Marxist view of social development. He did more than "accept" it: he tried to sketch the whole history of science from a Marxist viewpoint; he wrote a number of articles explicitly expounding his view of the relation of Marxism to science; and from his student days he played an active role in Communist politics. He has been criticised: during his lifetime, for too readily accepting official Soviet policy, whether relating to society or to science; since his death, for having been too ready to hope that his vision of the use of science for human ends could be implemented by capitalist societies; and at all times, for an allegedly simplistic faith in science as the salvation of mankind."

"I remember excitedly buying a boxed set of 4 books, Science in History by John D. Bernal (Pelican, 1965), when I was an undergraduate. At the time I was an amateur Marxist and Bernal’s work was an encyclopaedic analysis of science and society from a Marxist point of view. I was delighted to learn that Bernal was an Irishman who had spent a brilliant career at the leading edge of UK science, making many notable contributions."