The main argument of this paper is that philosophical difficulties regarding scientific discovery arise mainly because philosophers base their arguments on a flawed picture of scientific research. Careful examination of N. R. Hanson's treatment of Kepler's discovery not only puts the rationality of this discovery beyond question, it also reveals what its rationality consists in. We can retrieve the point stressed by Hanson concerning the rational character of discoveries such as Kepler's even as we reject the type of "logical" analysis (...) he proposes. (shrink)

This paper offers an answer to Glymour's ‘old evidence’ problem for Bayesian confirmation theory, and assesses some of the objections, in particular those recently aired by Chihara, that have been brought against that answer. The paper argues that these objections are easily dissolved, and goes on to show how the answer it proposes yields an intuitively satisfactory analysis of a problem recently discussed by Maher. Garber's, Niiniluoto's and others’ quite different answer to Glymour's problem is considered and rejected, and the (...) paper concludes with some brief reflections on the prediction/accommodation issue. (shrink)