Finishing the story of Toulmin’s critique of Kuhn. He traced the evolution of Kuhn’s ideas through five stages (1) his account in The Copernican Revolution (1957), (2) a public talk about revolutions at Worcester College in Oxford in 1961, (3) the first edition of The Structure of Scientific Revolutions published in 1962, (4) a series of papers written in response to criticism and (5) the revised edition of The Structure in 1970 and “Reflections on my critics” in Lakatos and Musgrave (eds) also 1970.
He concluded that the strong formulation involving paradigms and revolutions was designed for effect, to “shock the sensibilities” of the bourgeoisie like avant garde art. In response to criticism Kuhn had to water down the amount of change required for an episode to count as a revolution until the “mini revolutions” became so small and localized that he was left with the fairly familiar old idea that there is constant change in different parts of a vigorous field. Sometimes there is a much larger change (Copernicus-Kepler-Galileo-Newton and later Einstein) which has more far-reaching effects but the transition is not rapid or irrational and large areas of the discipline (not to mention science at large) are hardly perturbed by the process.
The debate lasted through most of the ‘60s and by 1965 Kuhn had shifted his focus from the rare occasions where there was major conceptual reform to less drastic episodes because even his prime cases were “somewhat less than ‘revolutionary’” in the technical sense hinted (but hardly defined) in The Structure of Scientific Revolutions. This meant that he watered down the extent of revolutions to allow for more and more “micro-revolutions!
So Kuhn “quietly abandoned the central distinction around which his theory had been built in the first place – that between conceptual changes taking place within the limits of an overall paradigm and those involving the replacement of an entire paradigm.” (114) Finally in the second edition of the book “Kuhn now complained” that his readers had taken too seriously the idea of paradigms as changes of world-view and all the ancillary apparatus of incommensurability and the like.
Toulmin suggested that authors may well revise their ideas in the light of misunderstandings by readers but in this case the earlier “misunderstood” ideas were a great deal more interesting than the revised version!
“and if this reinterpretation had been the whole truth, his original choice of the term ‘revolution’ was note merely a rhetorical exaggeration but something worse…that choice of phrase was grossly misleading; for it simply disguised a familiar logical distinction in an irrelevant historical fancy dress.” (115)