The PDA and Chance

Abstract

Abstract This chapter discusses how chance and objective probabilities fit into the Package Deal Account. The PDA adopts and develops Lewis’s account of objective probabilities by separating it from its reliance on perfectly natural properties. On the PDA laws including chance laws are entailed by a scientifically optimal systematization of the motions of macroscopic objects and whatever other phenomena introduced in this systematization. It is shown how on this understanding objective probabilities are compatible with deterministic dynamical laws. The PDA accommodates probability’s two faces. One face looks at the objective world; and the other at the mind. Lewis’s “Principal Principle” connects the two faces. The PDA modifies this principle and shows how it is rationalized as a principle for how chance laws provide information about events.