Published online by Cambridge University Press: 01 January 2022
According to David Lewis’s Principal Principle, our beliefs about the objective chances of outcomes (typically) determine our rational credences in those outcomes. Lewis influentially argues that any adequate metaphysics of objective chance must explain why the Principal Principle holds. Since no theory of chance is widely agreed to have met this burden, I suggest we change tack. On the view I develop, a central aspect of the Principal Principle holds not because of what objective chances are but rather because of the explanatory role that objective chances play for the rational agents who believe in them.
My thanks to Josh Armstrong, John Carriero, Daniela Dover, Gabriel Greenberg, Matthew Kotzen, Marc Lange, John Roberts, Seana Shiffrin, and four anonymous referees. Thanks also to audiences at California State University, Northridge; California State University, Los Angeles; and University of California, Irvine.