Projecting Chances: A Humean Vindication and Justification of the Principal Principle

Abstract

Faced with the paradox of undermining futures, Humeans have resigned themselves to accounts of chance that severely conflict with our intuitions. However, such resignation is premature: The problem is Humean Supervenience (HS), not Humeanism. This paper develops a projectivist Humeanism on which chance claims are understood as normative, rather than fact stating. Rationality constraints on the cotenability of norms and factual claims ground a factual-normative worlds semantics that, in addition to solving the Frege-Geach problem, delivers the intuitive set of possibilia for each chance law. Hence, the account does not entail HS, and the paradox does not arise. A confirmation theory is developed, and the Principal Principle is justified.