Abstract

Wesley Salmon and John Earman have presented influential Bayesian reconstructions of Thomas Kuhn's account of theory-change. In this paper I argue that all attempts to give a Bayesian reading of Kuhn's philosophy of science are fundamentally misguided due to the fact that Bayesian confirmation theory is in fact inconsistent with Kuhn's account. The reasons for this inconsistency are traced to the role the concept of incommensurability plays with reference to the 'observational vocabulary' within Kuhn's picture of scientific theories. The upshot of the discussion is that it is impossible to integrate both Kuhn's Claims and Bayesianism within a coherent account of theory-change.