You may have heard of the book The Structure of Scientific Revolutions, by the late Thomas Kuhn; it is arguably the most influential book ever written on the history and philosophy of science. In it, Kuhn examines the life cycle of a scientific “paradigm”, and the way that scientific communities pass from periods of “normal” science, during which research stays comfortably within the reigning paradigm, to “crises”, in which results begin to appear for which the current model cannot account, and during which more and more desperate efforts are made to preserve the existing view. An example of such a crisis would be the difficulties pre-relativistic physics found itself confronted with in the aftermath of the Michelson-Morley experiment.
Eventually, some breakthrough is made — a “scientific revolution” — and a new model is found that accommodates the troublesome data. Often this involves an entirely different understanding of the phenomena, and even of the nature of reality itself; Kuhn coined the now-familiar term “paradigm shift” to refer to this sort of reformulation.
Ever since 1962, when this important book was published to wide acclaim, postmodernist thinkers have seized on its description of the mutability of scientific views as evidence that science is little more than a social activity, and as support for the view that as such an activity, science should not be credited with telling us anything about objective truth. Even Kuhn himself, who should surely have known better, seems to have expressed some support for this opinion. He came to regard the paradigms prevailing before and after a scientific revolutions as “incommensurable”, meaning that the terms of each paradigm are so radically different that there can be no higher-level standard by which they can be compared; this means, then, that there is no objective sense in which successive scientific systems can be said to approach nearer and nearer to the truth.
This is catnip for postmodernists, of course, and they’ve had a field day with Kuhn’s book ever since. It’s just the sort of thing that radical academics need to support their dismissal of objectivity generally, and plays well when one is advocating against traditional interpretations of just about anything.
The great physicist Steven Weinberg, who knew, liked, and respected Kuhn, thinks that all of this has gone too far, and debunks such interpretations of Kuhn’s book in a characteristically lucid essay. Read it here, courtesy of Vladimir Lifschitz.