What Thomas Kuhn Really Thought about Scientific “Truth”

[Jim__]

John Horgan writes a somewhat meandering essay on Thomas Kuhn's thought as The Structure of Scientific Revolutions reaches 50 years of age. An excerpt from his article

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When we finally sat down together in his office, Kuhn expressed nominal discomfort at the notion of delving into the roots of his thought. “One is not one’s own historian, let alone one’s own psychoanalyst,” he warned me. He nonetheless traced his view of science to an epiphany he experienced in 1947, when he was working toward a doctorate in physics at Harvard. While reading Aristotle’s Physics, Kuhn had become astonished at how “wrong” it was. How could someone who wrote so brilliantly on so many topics be so misguided when it came to physics?

Kuhn was pondering this mystery, staring out his dormitory window (“I can still see the vines and the shade two thirds of the way down”), when suddenly Aristotle “made sense.” Kuhn realized that Aristotle invested basic concepts with different meanings than modern physicists did. Aristotle used the term “motion,” for example, to refer not just to change in position but to change in general—the reddening of the sun as well as its descent toward the horizon. Aristotle’s physics, understood on its own terms, was simply different from rather than inferior to Newtonian physics.

Kuhn left physics for philosophy, and he struggled for 15 years to transform his epiphany into the theory set forth in The Structure of Scientific Revolutions. The keystone of his model was the concept of a paradigm. Paradigm, pre-Kuhn, referred merely to an example that serves an educational purpose; amo, amas, amat, for instance, is a paradigm for teaching conjugations in Latin. Kuhn used the term to refer to a collection of procedures or ideas that instruct scientists, implicitly, what to believe and how to work. Most scientists never question the paradigm. They solve “puzzles,” problems whose solutions reinforce and extend the scope of the paradigm rather than challenging it. Kuhn called this “mopping up,” or “normal science.” There are always anomalies, phenomena that that the paradigm cannot account for or that even contradict it. Anomalies are often ignored, but if they accumulate they may trigger a revolution (also called a paradigm shift, although not originally by Kuhn), in which scientists abandon the old paradigm for a new one.

Denying the view of science as a continual building process, Kuhn held that a revolution is a destructive as well as a creative act. The proposer of a new paradigm stands on the shoulders of giants (to borrow Newton’s phrase) and then bashes them over the head. He or she is often young or new to the field, that is, not fully indoctrinated. Most scientists yield to a new paradigm reluctantly. They often do not understand it, and they have no objective rules by which to judge it. Different paradigms have no common standard for comparison; they are “incommensurable,” to use Kuhn’s term. Proponents of different paradigms can argue forever without resolving their basic differences because they invest basic terms—motion, particle, space, time—with different meanings. The conversion of scientists is thus both a subjective and political process. It may involve sudden, intuitive understanding—like that finally achieved by Kuhn as he pondered Aristotle. Yet scientists often adopt a paradigm simply because it is backed by others with strong reputations or by a majority of the community.

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[eridani]

1. I much prefer Stephen Toulmin's concept of science as making reality maps

A map of WA State does not become wrong when you cross the Columbia--it just applies to the wrong territory. Kuhn ignores the historical grounding of science. Einstein's map just covers more territory than Newton's--the latter still works if masses aren't too large or moving very fast.

[phantom power]

2. this is a bit too relativist for me:

"Aristotle’s physics, understood on its own terms, was simply different from rather than inferior to Newtonian physics."

Aristotle's physics was unambiguously inferior to Newton's physics in terms of explaining and predicting. Newton's physics explained much more, much better.

There's a reason that paradigm shifts happen infrequently: to be accepted, a new paradigm has to successfully explain everything the current one does, and then also explain some new things. It has to be better, not just "different."

It's why you can't just toss out any old "new grand unified theory." You've got to be able to encompass everything that is successfully explained by the standard model and relativity, which is a hell of a lot, even though everybody is perfectly aware it's not everything.

[Jim__]

3. That quote is John Horgan, not Kuhn, and is symptomatic of Kuhn's complaint about the press.

Here is a excerpt from a short essay by Kuhn on Aristotelian physics. I understand Kuhn to be saying that Aristotle's physics is consistent and coherent when understood on its own terms. It's Horgan's statement that is, at best, misleading.

I first read some of Aristotle's physical writings in the summer of 1947, at which time I was a graduate student of physiccs trying to prepare a case study on the development of mechanics for a course in science for nonscientists. Not surprisingly, I approached Aristotle's texts with the Newtonian mechanics I had previously read clearly in mind. The question I hoped to answer was how much mechanics Aristotle had known, how much he had left for people like Galileo and Newton to discover. Given that formulation, I rapidly discovered that Aristotle had known almost no mechanics at all. Everything was left for his successors, mostly those of the sixteenth and seventeenth centuries. That conclusion was standard, and it might in principle have been right. But I found it bothersome because, as I was reading him, Aristotle appeared not only ignorant of mechanics, but a dreadfully bad physical scientist as well. About motion, in particular, his writings seemed to me full of egregious errors, both of logic and of observation.

These conditions were unlikely. Aristotle, after all, had been the much admired codifer of ancient logic. For almost two millennia after his death, his work played the same role in logic tht Euclid's played in geometry. In addition, Aristotle had often proved an extraordinarily acute naturalistic observer. In biology, especially, his descriptive writings provided models that were central in the sixteenth and seventeenth centuries to the emergence of the modern biological tradition. 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? Those questions troubled me. I could easily believe that Aristotle had stumbled, but not that, on entering physics, he had totally collapsed. Might not the fault be mine rather than Aristotle's, I asked myself. Perhaps his words had not always meant to him and his contemporaries quite what they meant to me and mine.

Feeling that way, I continued to puzzle over the text, and my suspicions ultimately proved well-founded. I was sitting at my desk with the text of Aristotle's Physics open in front of me and with a four-colored pencil in my hand. Looking up, I gazed abstractedly out the window of my room -- the visual image is one I still retain. 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 piecemeal, 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.

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Those remarks, though both simplified and incomplete, should sufficiently illustrate the way in which Aristotelian physics cuts up and describes the phenomenal world. Also, and more important, they should indicate how the pieces of that description lock together to form an integral whole, one that had to be broken and reformed on the road to Newtonian mechanics.

[Odin2005]

4. I prefer Popper over Kuhn.

Besides the fact that Kuhn confuses the sociology of the scientific community with the philosophy of science, I think he greatly exaggerates the difference between "normal science" and "revolutionary science", a distinction that I think only applies when a particular scientific field is young and is still looking for it's foundation. When that foundation is found the foundation may be renovated and added on to, but it is never replaced.

The foundations of the various fields are:

Physics and Chemistry: Classical Mechanics

Biology: The Modern Synthesis ("Neo-Darwinism&quot

Geology: Plate Tectonics

Once the foundations are found, they are not replaced, they become a special case within a more complete theory