Abstract

I argue that a recent variation on the Sleeping Beauty case due to Titelbaum [2012a] puts significant pressure on Lewis's theory of doxastic content—the theory of content that Titelbaum and others presuppose. In particular, that theory cannot make sense of the rational constraints on credences imposed by the Principal Principle, as ordinarily understood. I then argue more generally that any theory on which contents of credences are sets of centered worlds cannot adequately represent all of the rational constraints on credences.