Abstract

In this paper I wish to offer a suggestion in support of the thesis that if a given set of facts is explained by two rival explanations A and B, where A consists of a single hypothesis H1, and B consists of at least two independent hypotheses H2 and H3, then, other things being equal, A is more probable than B. That this view is true is seldom questioned, though I have never seen any reason given for it, which would justify the methodological value so many philosophers attribute to it. It is not my purpose to discuss simplicity of explanation in general, but simply to point out that the Multiplicative Axiom of the calculus of probabilities justifies the above thesis. I shall call this thesis the Principle of Parsimony.