 Rawls says that in the original position, “the Reasonable frames the Rational” (CP 319). He means the OP is a situation where rational choice of the parties is made subject to reasonable (or moral) constraints. In what sense are the parties and their choice and agreement rational? Philosophers have different understandings of practical rationality. Rawls seeks to incorporate a relatively uncontroversial account of rationality into the original position, one that he thinks most any account of practical rationality would endorse as at least necessary for rational decision. The parties are then described as rational in a formal or “thin” sense that is characteristic of the theories of rational and social choice. They are resourceful, take effective means to their ends, and seek to make their preferences consistent. They also take the course of action that is more likely to achieve their ends (other things being equal). And they choose courses of action that satisfy more rather than fewer of their purposes. Rawls calls these principles of rational choice the “counting principles” (TJ sect. 25, JF 87). 