David Weinberger discusses Kuhn’s The Structure of Scientific Revolutions in a recent article at the Chronicle of Higher Education. I want to discuss that here, because it illustrates where I disagree with much of what is written as philosophy of science.
By far the most consistently attacked idea was what Kuhn referred to as incommensurability, a term taken from geometry, where it refers to the lack of a shared measurement. In SSR it means something like the inability to understand one paradigm from within another. In the book, Kuhn borders on putting incommensurability in its strongest imaginable form: A new paradigm causes scientists to “see the world of their researcher-engagement differently. In so far as their only recourse to that world is through what they see and do, we may want to say that after a revolution scientists are responding to a different world.”
I did think Kuhn was overstating things with his reference to “a different world.” He should have omitted that last quoted sentence.
Weinberger continues with:
To overstate it: The scientists hated incommensurability because it seemed to imply that science makes no real progress, the philosophers hated it because it seemed to imply that there is no truth, and the positivists hated it because it seemed to imply that science is based on nonrational decisions.
I don’t recall talking to any scientist who hated Kuhn’s thesis. I have found several who thought that Kuhn made some good points.
The use of “incommensurable” in geometry is in saying that the diagonal of a square in incommensurable with the side of the square. As far as I know, almost anybody could tell that the diagonal was a little less than 1.5 times the length of the side. The “incommensurability” referred to the fact that it was not an exact rational multiple, and in an era before irrational numbers had come into use, that meant that you could not exactly express the length of the diagonal. Analogously, I saw Kuhn’s incommensurability thesis as stating that statements from one paradigm could not be exactly translated into statements from another paradigm. And that seemed true enough.
In the case of the paradigm shift from Newtonian mechanics to relativity, some philosophers seem to take the view that there are direct contradictions, and I suppose that is what leads to the comment about truth. But most scientists don’t see it that way at all. They tend to see relativity as a refinement of Newtonian science, albeit a refinement that is sometimes harder to use.
Using relativity, one describes the world differently from the way that a Newtonian would have described it. However, scientists see it is the same world being described in different ways. Some philosophers seem to see the different descriptions as contradictory. I guess this gets back to the point I tried to make in an earlier post, that philosophers seem to be looking at the syntactic aspects of the description, while scientists are looking at the semantics.
On a similar note, Michael Ruse recently wrote:
For us philosophers of science, the big problem back then was the extent to which science can be said to be a disinterested picture of objective reality and to what extent it is a “social construction,” an epiphenomenon of the culture or society (especially the values) of the day.
But why would he think those are incompatible? There’s no doubt that the camera is a social construction, yet the photographs it takes seem to present a reasonably disinterested picture of some part of the world. And that’s a point I tried to make in my earlier posts on the camera analogy.
The Heretical Philosopher 