In Chapter 9 we consider a range of further matters to do with Bayesianism such as: whether the rules of the probability calculus need supplementation in order to provide a theory of scienti c method; the problem of priors; its account of new and old evidence; the extent to which it can accommodate aspects of inference to the best explanation; what justi cation of induction it can provide; and its account of some of the values and rules mentioned in Part I. Although there are some successes, there are also some shortcomings to note. Whatever the verdict on Bayesianism as an overall theory of method, it is the pivot around which much current work in methodology turns.