A good book may have the power to change the way we see the world, but a great book actually becomes part of our daily consciousness, pervading our thinking to the point that we take it for granted, and we forget how provocative and challenging its ideas once were--and still are. The Structure of Scientific Revolutions is that kind of book. When it was first published in 1962, it was a landmark event in the history and philosophy of science. Fifty years later, it still has many lessons to teach. With The Structure of Scientific Revolutions, Kuhn challenged long-standing linear notions of scientific progress, arguing that transformative ideas don't arise from the day-to-day, gradual process of experimentation and data accumulation but that the revolutions in science, those breakthrough moments that disrupt accepted thinking and offer unanticipated ideas, occur outside of "normal science," as he called it. Though Kuhn was writing when physics ruled the sciences, his ideas on how scientific revolutions bring order to the anomalies that amass over time in research experiments are still instructive in our biotech age. This new edition of Kuhn's essential work in the history of science includes an insightful introduction by Ian Hacking, which clarifies terms popularized by Kuhn, including paradigm and incommensurability, and applies Kuhn's ideas to the science of today. Usefully keyed to the separate sections of the book, Hacking's introduction provides important background information as well as a contemporary context. Newly designed, with an expanded index, this edition will be eagerly welcomed by the next generation of readers seeking to understand the history of our perspectives on science.
Thanks to the Chomskies, Dawkinses and Sokals of this world, who have cunningly bound perfectly sensible Cognitive and Ethical Relativism to silly Post-Structuralism, proper Relativism has become a dirty word these days.
It may be unfashionable but it's also powerful, and if you want to understand it, and its power, The Structure of Scientific Revolutions - as short and beautifully written a classic of philosophy as you could possibly ask for - is as good a place as any to start.
Following publication of "Structure", Kuhn had a famous public debate with Karl Popper over what counts as science and the way in which science develops over time. Popper had, in The Logic of Scientific Discovery, made the invaluable observation that "verification" as a standard for science is too high, since as a matter of logic an argument based on induction ("since the sun has risen on every day in recorded history, therefore it will rise tomorrow") can never be proven true. The sun rising is a very good example: for all our folksy expectations, current cosmology predicts that there will be a point at some time in the distant future when the sun will explode, and therefore will not rise tomorrow.
In lieu of verification as the scientific gold standard, Popper asserted (seemingly plausibly) that valid scientific theory could be assessed by the lack of any falsifying evidence among the data. The requirement for scientific statements to be "falsifiable" is a useful contribution to the debate: To be of any use, a scientific theory must narrow down from the list of all possible outcomes a set of predicted ones, and rule the rest out. Statements which cannot be falsified by any conceivable evidence don't do that, so fail at science's fundamental task.
Thomas Kuhn's insight was to offer a historian's perspective, and to note that, while that might be theory, that's simply not what science does in practice. Scientific theories are absolutely never thrown out the moment contradictory evidence is observed: the dial is tapped, the experiment re-run, and "numerous articulations and ad hoc modifications of their theory" are devised to eliminate any apparent conflict. Indeed, when the data won't do what it's meant to, sometimes it is the question which is rejected as being irrelevant, and not the answer predicted by the theory.
All this activity takes place inside what Kuhn describes (somewhat inconsistently) as a "paradigm" - a "particular coherent tradition of scientific research". The paradigm governs not only the theory but the education, instrumentation, rules and standards of scientific practice, and is the basis on which the scientific community decides which kinds of questions are and are not relevant to the development of scientific research. A paradigm claims exclusivity over the adjudication of its own subject matter, and one only has authority to pronounce on a scientific problem once one has been fully inducted: evolutionary biologists will not take seriously the biological assertions of fundamentalist Christians, for example. Fundamentalist Christians who take biology exams will fail, and thereby will never be able to authoritatively comment on biological matters.
Paradigms are generally a useful thing for the jobbing scientist, since to her they provide a pre-agreed framework - what Dan Dennett would describe as a "crane" - on which additional scientific research can be undertaken without having, literally, to re-invent the wheel. Kuhn characterises this sort of "normal scientist" as being involved in "puzzle solving" in exactly the sense that one solves a crossword puzzle. You have a framework of rules for how to solve the puzzle; you have problems (the blank spaces on the puzzle) and you empirically obtained evidence (clues) which you manipulate using the rules to produce predictions (or answers), and each newly discovered answer then acts as an additional clue to solve the remaining problems.
Superficially, this all sounds fine, but there are brutal, jagged corals just below the water's surface: Once inside a paradigm it informs your view of the world so thoroughly it is not possible to conduct research outside it. To solve a crossword puzzle, there must first be *some* pre-determined rules of engagement (the same puzzle can be solved, differently, with different sets of rules: a "cryptic" crossword yields different answers for the same boxes, and perhaps even the same clues, to a "quick" crossword. But to solve it one needs to use one or the other). Unlike a crossword, Mother Nature doesn't come with a label saying "cryptic" or "quick". So how do we know which paradigm to use? Can the truth or falsity of the paradigm to be judged, other than in terms of the paradigm itself?
Kuhn says no. This is an immensely powerful idea. Not only does it undermine the certitude many people have about their own ways of life, it seems to opens the door to all the whacky alternatives, with no objective means of choosing between them. So can we really not choose between Radiotherapy and Healing Crystals?
That this might be the case terrifies a lot of people, especially scientists, and Kuhn gets a lot of the blame for this state of unease. Post-Modernism: It's all Kuhn's fault.
But this is surely to shoot the messenger: Kuhn's great contribution is not to say that healing crystals are in (he says nothing of the sort) but to say that the sacred and immutable link between science and truth is out, and we owe it to ourselves to keep an open mind about whatever we believe. After all, the history of science (which is what Kuhn started out writing about) is a long history of frequent revolution. Either all the theories scientists have ever believed up to the current day are baloney, always were, never really counted as science and we're just lucky to be around when the human race has finally got it right - which, to put it mildly, is wishful thinking - or the revolutionary history of science, which no-one disputes, tends to back up what Kuhn is saying.
Science does evolve, through the great algorithm of human discourse, and the dominating theories through time will tend to be the ones which most of us are persuaded work the best for us (whether we're right or not is really beside the point). What persuades in Tehran may differ from what persuades in Texas. All Thomas Kuhn cautions against is either side taking its own position as a given.
His enterprise is therefore fundamentally democratic - placing epistemological legitimacy in the hands of the entire community, as contingent and random as it may be from time to time, and not a self-selecting, self perpetuating elite.
One thing economic theory tells us is that concentrating economic control in a small part of the population (as in a monopoly) generally works out worse for everyone except the monopolist. There's no reason to suppose that concentrating intellectual authority should be any different.
In the Western Hemisphere - outside the Grateful Dead tour circuit, at any rate - intellectual authority mostly resides with established science, but it has to work - literally - to earn our respect.
The anti-Kuhn brigade like Richard Dawkins may not like that sort of accountability but, not being a scientist, I do.
Science advances in two ways. One of these is by adding new layers to a structure of derivative worldview beliefs. This involves a competition between old and new ideas. Kuhn draws a parallel with natural selection. Hence the successful development of scientific worldviews correspond to survival of the most appealing (fittest) beliefs. Yet natural selection has no plan. Thus we should not rely upon science’s ‘improving’ (evolving) record to conclude that there is an ultimate truth to which science is advancing. This is his most unpalatable conclusion. He undermines an argument; he does not rule out the existence of an ultimate truth.
Furthermore Kuhn points out that paradigm shifts deal with beliefs. Thus there is no neutral way of assessing proposed changes. A challenging worldview and the existing worldview are incommensurate; they judge things in very different terms. Thus the adding of a new lower level (or even the replacement of the existing lowest level) takes time and is mentally taxing for those involved.
Wrong, says Kuhn. Science in any given era is ruled by a paradigm, an over-arching theory that answers the big questions, and determines the bounds and the context within which everyday research takes place. Kuhn calls this everyday research "normal science," and its purpose is to flesh out and confirm the predictions of the paradigm.
At a certain point in the life of the paradigm, anomalies begin to appear. At first they are rationalized, as the paradigm is stretched and patched up to account for them. But eventually the anomalies become too glaring. Someone then comes along and proposes a bold new paradigm that completely replaces the old one. For example, Einstein's theory of relativity supplanting the former Newtonian system. Once the skeptics are defeated and the new paradigm is universally accepted, normal science resumes, but exclusively within the framework of the new paradigm.
In Kuhn's words:
"Sometimes a normal problem, one that ought to be solvable by known rules and procedures, resists the reiterated onslaught of the ablest members of the group within whose competence it falls. On other occasions a piece of equipment designed and constructed for the purpose of normal research fails to perform in the anticipated manner, revealing an anomaly that cannot, despite repeated effort, be aligned with professional expectation. In these and other ways besides, normal science repeatedly goes astray. And when it does--when, that is, the profession can no longer evade anomalies that subvert the existing tradition of scientific practice--then begin the extraordinary investigations that lead the profession at last to a new set of commitments, a new basis for the practice of science. The extraordinary episodes in which that shift of professional commitments occurs are the ones known in this essay as scientific revolutions."
At this juncture, I find myself somewhat in sympathy with Kuhn. One can think of several cases that seem to correspond to this process, a prominent one being Darwin's theory of evolution. It was certainly revolutionary, and "normal science" has busied itself with filling out the theory and--more recently--with wildly bailing out the sinking ship. One can imagine a new scientific paradigm emerging, causing Darwin to be relegated entirely to the history books.
The problem begins when Kuhn goes beyond merely illuminating the great revolutions that have occurred in scientific thought. These revolutions, for him, completely supplant the previous view; in fact, they create a new truth. There is no such thing as an objective, empirically verifiable fact. The only thing that can be verified is a given phenomenon in relation to the ruling paradigm.
In the exposition of this argument, Kuhn reveals his relativistic hand by wading in the muddy waters of experimental psychology, which showed radical shifts in perception based on the beliefs and expectations of the test subject:
"An experimental subject who puts on goggles fitted with inverting lenses initially sees the entire world upside down. At the start his perceptual apparatus functions as it had been trained to function in the absence of the goggles, and the result is extreme disorientation, an acute personal crisis. But after the subject has begun to learn to deal with his new world, his entire visual field flips over, usually after an intervening period in which vision is simply confused. Thereafter, objects are again seen as they had been before the goggles were put on. The assimilation of a previously anomalous visual field has reacted upon and changed the field itself. Literally as well as metaphorically, the man accustomed to inverting lenses has undergone a revolutionary transformation of vision."
These "revolutionary transformations of vision," says Kuhn, are equally applicable to the world of science:
"After a revolution, scientists are responding to a different world. It is as elementary prototypes for these transformations of the scientist's world that the familiar demonstrations of a switch in visual gestalt prove so suggestive. What were ducks in the scientist's world before the revolution are rabbits afterwards...Transformations like these, though usually more gradual and almost always irreversible, are common concomitants of scientific training. Looking at a contour map, the student sees lines on paper, the cartographer a picture of a terrain. Looking at a bubble-chamber photograph, the student sees confused and broken lines, the physicist a record of familiar subnuclear events."
As an exercise, let us apply Kuhn's method to Kuhn himself. We begin the exercise by saying that for thousands of years, at least since Aristotle, the reigning epistemological paradigm was that science is based on objective, verifiable facts. But more and more anomalies were found; modern thinkers noticed that the ideas of different individuals, groups, and nations are dependent upon a set of received values and beliefs. Thus who is to say which of the systems represents the truth? Along comes Kuhn and applies this modern relativistic approach to the last great bastion of objective truth: science itself.
Now, continuing our Kuhnian analysis of Kuhn: This paradigm, in its numerous permutations, has been in vogue for quite some time, going back at least to Hegel. Even looking at Kuhn alone, it is now nearly half a century since the publication of "The Structure of Scientific Revolutions." Anomalies are accumulating, and we begin to realize that relativism is...well...relative. Kuhn's theory is merely one more paradigm that inevitably will be replaced. Are not relativism and its derivatives (such as deconstructionism and multiculturalism) dependent upon a received set of values and beliefs, just like any other theory?
Thus the paradox of relativism: If everything is relative, and there are no real "truths," then we have no reason to accept relativism itself as more valid and "true" than anything else. It can be deconstructed and thrown out like any other notion.
Like its ideological cousin, Marxism, Kuhnian relativism refuses to admit the existence of a world, with its laws, its nature, and its continuity. It refuses to admit that we and Aristotle are looking at the same rock. Certainly, our interpretations differ, but the rock remains the same, notwithstanding some gestalt hocus-pocus that tricks us into seeing the rock upside-down.
Kuhn's remark that ducks become rabbits as a result of a scientific revolution brings to mind the following statement by Aristotle (in "The Metaphysics") on the intellectual short-circuit that occurs in philosophical relativism:
"If all contradictions are true at the same time of the same thing, palpably all things will then be one. For if it is possible either to affirm or to deny anything of everything, the same thing will be a ship and a wall and a man, as it must be for those who repeat the theory of [the relativist] Protagoras. Then if anyone thinks that a man is not a ship, undoubtedly he is not a ship. But, in the same way, he is a ship, if the contrary is true....I mean that if it is true to say that a man is not a man, then clearly it is also true that he is a ship and not a ship....Then all things will be one, as we said before, and the same thing will be man and God and ship and their opposites. For if we can make all these assertions of everything, there will be no difference between any one thing and any other...
"And if all men are equally wrong and right, a person like that can neither speak nor tell us anything, for he is saying at the same time both "yes" and "no." And if he has no opinion but both thinks and does not think together, how is he different than a vegetable? So it is very evident that no one, neither those who profess this theory nor any others, really abide by it....When he wants and looks for a drink of water or a man to see, he does not go looking for everything and taking them all to be the same; and yet he should, if the same thing were equally a man and not a man."
The text is exactly how you'd expect a book that was written by a scientist turned philosopher to turn out: dense and Socratic. A passing familiarity with the histories of astronomy/Copernicus/Kepler, gravity/Newton, oxygen/Lavoisier, electricity/Maxwell, relativity/Einstein will help you understand what Kuhn is talking about — he doesn't offer much in the realm of narrative history. The book is structured around an argument, not a chronology, so it skips around from period to period, mining examples for the thesis that normal science is substantively different from revolutionary science.
A quick summary for this book evades me, probably because there's a lot of territory covered, including the training of scientists, normal and revolutionary science, why anomalies accrue in some disciplines and never create new theories (or create new theories in other disciplines), the meaning of objectivity and observation, etc. I don't remember Schrödinger's cat in there, but maybe I missed it. Despite the breadth, you don't get the sense that Kuhn is ranging out of his expertise, and he also makes some points more precise in the postscript from 1969.
What I most like about Structure is the idea that incommensurable ways of seeing the world are still both scientific. There's a way of telling the story of scientific discovery that makes people who used to operate on the theory of phlogiston look stupid, which is a disservice to both history and science, not to mention insulting to very intelligent researchers who spent careers doing productive work.
There are some who will find Kuhn lacking all coherence (sophisticated BS, as one reviewer put it), and that is another way of saying "irrational". For those who associate irrationality with things like religious fundamentalism, irrationalism is a fearful thing. Yet, it is rationality itself that has been called into question (the crisis of modernity) by the events of the 20th century, beginning with the carnage of WWI. The answer is not more rationalism (if people would only try to "understand") --- rationalism, the primacy of reason, is itself a belief. The answer may be, as Rorty has pointed out, what we want to belief. That may be a fearful thing for those who don't find complete correspondence between their beliefs and Rorty's privileged beliefs. What, though, it does show, is that irrationality is not sufficient grounds for being dismissive. In doing so one may be taking a stance on the wrong side of the arrow of history.
The arrow, though, is not that of the Whig theory of history, where things constantly improve driven by reason. Historians of this view (as well as much of popular culture) denigrate older views by degrading them to myth or religious belief status, This gives a privileged position to our own, contemporary beliefs and gives us a sense of comfort. Kuhn disturbs this comfortable view by showing, for example, that Ptolemaic astronomy gave plausible answers to questions of the day. So too, one could argue that the contemporary dismissive view of Scholastic philosophy is more the result of Enlightenment propaganda than of merit. At the least, Kuhn is a good (partial) antidote for contemporary smugness --- a challenge to bourgeois sentiment. Kuhn, though, is much more than a cultural caution; he is an important voice in the contemporary philosophical debate
The theses of this work are fairly well know, to those who would come looking for it, so I will not get into that. Rather I will say that this is a book that deserves a re-reading or two (or three) for the nuance that runs all throughout it. I will certainly be
Not directly incompatible with either the earlier work of Popper, or the later work of Feyerabend, Kuhn proposes that Science alternates through two phases – the relatively stable “normal science” phase of problem solving and tying up loose ends within a paradigm (measuring stuff to validate theoretical predictions etc.), and the “crisis” phase where the paradigm (or worldview) has to be replaced due to an accumulating body of phenomena that don’t fit in with the predictions of the current theoretical framework. During the latter, competing schools obtain evidence to support alternative candidate worldviews (theories), with the one producing the best evidence, and most explanatory theory winning out after a period of chaos. Then a period of normal science ensues, then another revolution. Whether this goes on forever, or whether we eventually reach a fully satisfactory explanation of all observed phenomena is not discussed at length.
A revolution and paradigm shift in one field, for example understanding of electricity, might or might not particularly affect science in another field, with some minor revolutions being quite self-contained within a specialism, and others affecting many other adjacent disciplines. What sets out a revolution, or paradigm shift, from a development in normal science, is the entire change in underlying theoretical framework (or paradigm) relating to a set of phenomena. So, the transition from gravity being explained by Newtonian equations to Einsteinian equations (relativity) would count, whereas the application of Einstein’s equations to predict the existence of black holes, or that the universe began as a singularity (with or without any evidence to support these predictions), would not count as a paradigm shift, as these are entirely compatible with the existing framework of Relativity. Unfortunately the term “Paradigm shift” has entered common usage with little care for what it actually means.
Kuhn also discusses the consequences of revolutions and presents his ideas on incommensurability – how words and scientific concepts no longer mean the same things after a paradigm shift, how we see the world in a different way. How the meaning of the old terms cannot be directly translated into something that can be fully understood within the framework of the new worldview. This has certain consequences, especially during the time of transition when scientists operating within competing frameworks struggle to find a common language, and end up talking at cross purposes.
A classic deserving to be on the reading list for anyone interested in the philosophy or history of science, or science in general.
This progress is, as Kuhn tells it, not entirely linear. Often scientists will disagree about "paradigm shifts" among scientific theories. Often, the older generation does not embrace a new paradigm (or exemplar) entirely. Only a new generation will bring a new theory into dominance while the holdouts disappear to the wayside. Sometimes, famous scientists are the holdouts (as was seen, say, with the discovery of oxygen).
Scientific paradigms are groups of practices, people, and ways of thinking about the world. Paradigms are not right and wrong (true to Kuhn's linguistic form, in which field he taught at MIT). Paradigms are instead expressive.
Paradigms are established often by young people new to the field who reorganize it in light of other learning. These revolutions only rarely succeed, but when they do, textbooks are changed. Thus, the next generation embraces the new paradigm. Unlike other fields of knowledge, textbooks take central place in this story.
From there, normal science (non-paradigm-shifting science) rules. In normal science, people work on solving "puzzles" within existing paradigms. When a new paradigm comes about, these puzzles shift to address new issues. Originally, a "crisis" occurs in the scientific community as to whether to embrace the new ways of thinking. When the positives of the new situation outweigh the old paradigm, a shift occurs, and work continues in the new paradigm.
As such Aristotle need not be viewed as ignorant or unhelpful vis-a-vis Isaac Newton - or Newton, vis-a-vis Albert Einstein. They are just different paradigms that express their findings differently. Many might complain that this takes truth out of science in favor of a sophisticated relativity, and it does. Nonetheless, it redeems the past and the history of science. By studying history (one of my favorite past times), we grow in our creative knowledge. I like this, and I like the way Kuhn thinks.
Kuhn reminds me of how Christians think about conversion. There is a "crisis" (cf. Karl Barth) and a conversion to a new paradigm. This has occurred over and over again in theological history. Why not see this essentially human practice in science, too?
If you know a scientist who has NOT read this... see if you can rectify that situation....
Also. This is my footnote to the Ian Hacking
The word paradigm has two usages: the exemplary case and the standard model. The first is in the realm of fact and the second is in the realm of theory. When Kuhn popularized the word in Structure of Scientific Revolutions he was using it in the first sense. Now the word is mostly used in the second.
Kuhn's work is immediately incredible. Though it's probably not always right, it's not always right in the way that most big ideas are, because it's so big that there can't not be tons of little exceptions to what he says and how he says it. His model of science, as a series of paradigms that shift but don't necessarily become more truthful, just more useful, is immediately persuasive. I especially liked what he said about the action of "normal science," the science that happens between paradigms. Despite the fact that scientists know that major theories are overturned throughout history and will be overturned again, they all proceed as though science has been settled and do these small tiny experiments.
I also liked his concept of "paradigm vision" (I don't think he calls it this exactly, but I do), that scientists see the world through the lens of their paradigms, and indeed, often find it impossible to bridge the gap between paradigms because it affects the language they uses. I thought of the Pluto-is-a-planet thing when reading this section; some people cannot believe that Pluto is not a planet because they see the world in such a way that the word "planet" means something that includes Pluto. How could they possibly accept that it is not a planet?
Of course, Kuhn's ideas are more applicable to physics than other sciences, and rejecting the sciences they don't fit as "immature" is probably not the right solution, but that doesn't stop it from being interesting. I am kinda disgruntled that Kuhn added an afterword in 1969 to deal with criticisms that had been lobbed at it, instead of actually integrating the criticisms into the main text. But on the other hand, I'm glad that his response to that criticism can be safely contained in one chapter because the criticisms are all such nitpicky philosophy of science bullshit.