Abstract

I respond to Allan Franklin's critique of my account of the establishment of parity-violating neutral-current effects in atomic and high-energy physics as an instance of a more general 'rationalist' attack on 'constructivist' understandings of science. I argue that constructivism does not entail the denial of 'reason' in science, but I note that there are typically too many 'reasons' to be found for 'reason' to count as an explanation of why science changes as it does. I show, first, that there were many 'reasonable' but different ways of reasoning about the field of evidence at issue in this episode and, second, that Franklin's articulation of how theory-choice should proceed on the basis of evidence implies a vicious conservatism which is fortunately not to be found in the history of science.