tecznotes

I first heard the term "paradigm shift" in high school (journalism camp, 1994, oh yeah). It gets used a lot these days, especially in the field of web technology, where every new web service, development framework, and business plan is a game changing paradigm shift. Curious where the term originated, I was led to Thomas S. Kuhn's The Structure of Scientific Revolutions, a 1962 essay seeking to explain changes in scientific belief over time. Kuhn's central argument is that progress does not happen by slow accretion of ideas over time, but by periods of stable work ("normal science") punctuated by crisis and rapid change ("paradigm shifts"). Crises are brought about by an accumulation of problems closed to normal scientific work, and are resolved through gestalt shifts that change research agendas and dominant theories.

The book also includes a 1969 postscript that flips the impact of the book on its head a bit. I've always seen the essay's argument as broadly applicable to other fields, but Kuhn says he developed it by applying the lessons of other fields to science.

Page 208, on applicability:

To one last reaction to this book, my answer must be of a different sort. A number of those who have taken pleasure from it have done so less because it illuminates science than because they read its main theses as applicable to many other fields as well. I see what they mean and would not like to discourage their attempts to extend the position, but their reaction has nevertheless puzzled me. To the extent that the book portrays scientific development as a succession of tradition-bounds periods punctuated by non-cumulative breaks, its theses are undoubtedly of wide applicability. But they should be, for they are borrowed from other fields. Historians of literature, of music, of the arts, of political development, and of many other human activities have long described their subjects in the same way. Periodization in terms of revolutionary breaks in style, taste, and institutional structure have been among their standard tools. If I have been original with respect to concepts like these, it has mainly been by applying them to the sciences, fields which had been widely though to develop in a different way.

On to the meat of the book...

Pages 2-3, on what is scientific:

The more carefully they study, say, Aristotelian dynamics, phlogistic chemistry, or caloric thermodynamics, the more certain they feel that those once current view of nature were, as a whole, neither less scientific nor more the product of human idiosyncrasy than those current today. ... Out-of-date theories are not in principle unscientific because they have been discarded.

Page 5, on normalcy:

Normal science, the activity in which most scientists inevitably spend most all their time, is predicated on the assumption that the scientific community knows what the world is like. Much of the success of the enterprise derives from the community's willingness to defend that assumption, if necessary at considerable cost. Normal science, for example, often suppresses fundamental novelties because they are necessarily subversive of its basic commitments. Nevertheless, so long as those commitments retain an element of the arbitrary, the very nature of normal research ensures that novelty shall not be suppressed for very long.

Page 20, on the coincidence of intelligibility and paradigm boundaries:

Both in mathematics and astronomy, research reports had ceased already in antiquity to be intelligible to a generally educated audience. In dynamics, research became similarly esoteric in the later Middle Ages, and it recaptured general intelligibility only briefly during the early seventeenth centrury when a new paradigm replaced the one that had guided medieval research. Electrical research began to require translation for the layman before the end of the eighteenth century, and most other fields of physical science ceased to be generally accessible in the nineteenth.

Page 55, on discovering:

Clearly we need a new vocabulary and concepts for analyzing events like the discovery of oxygen. Though undoubtedly correct, the sentence, "Oxygen was discovered," misleads by suggesting that discovering something is a single simple act assimilable to our usual concept of seeing. That is why we so readily assume that discovering, like seeing or touching, should be unequivocally attributable to an individual and to a moment in time. But the latter attribution is always impossible, and the former often is as well.

Page 76, on crisis and retooling paradigms:

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.

Page 88, on introspection during crisis:

It is no accident that the emergence of Newtonian physics in the seventeenth century and of relativity and quantum mechanics in the twentieth should have both been preceded and accompanied by fundamental philosophical analyses of the contemporary research tradition. Nor is it an accident that in both of these periods the so-called thought experiment should have played so critical a role in the progress of research. As I have shown elsewhere, the analytical thought experimentation that bulks so large in the writings of Galileo, Einstein, Bohr, and others is perfectly calculated to expose the old paradigm to existing knowledge in ways that isolate the root of crisis with a clarity unattainable in the laboratory.

Page 122, on the suddenness of paradigm shifts:

Paradigms are not corrigible by normal science at all. Instead, as we have already seen, normal science ultimately leads only to the recognition of anomalies and to crises. And these are terminated, not by deliberation and interpretation, but by a relatively sudden and unstructured event like the gestalt switch. Scientists 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.

Pages 150-151, on generational shifts:

How, then, are scientists brought to make this transposition? Part of the answer is that they are very often not. Corpernicanism made few converts for almost a century after Copernicus' death. Newton's work was not generally accepted, particularly on the Continent, for more than half a century after the Principia appeared. ... And Max Planck, surveying his own career in his Scientific Autobiography, sadly remarked that "a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die."

Page 164, on choice of problem:

Unlike the engineer, and many doctors, and most theologians, the scientist need not choose problems because they urgently need solution and without regard for the tools available to solve them. In this respect, also, the contrast between natural scientists and many social scientists proves instructive. The latter often tend, as the former almost never do, to defend their choice of a research problem - e.g. the effects of racial discrimination or the causes of a business cycle - chiefly in terms of the social importance of achieving a solution. Which group would one then expect to solve problems at a more rapid rate?