John Rawls introduces goodness as rationality as his formal account of a person’s good within justice as fairness. This formal account holds for both the so-called “thin theory” of the good that Rawls uses in setting up the original position and the full theory of the good applicable to citizens in a well-ordered society. The account holds that a person’s good is given by the plan of life he or she would arrive at under ideal conditions of deliberation. Rawls defines goodness over three stages. At each stage, the thought is that we can, without altering truth values, substitute talk of the properties that it is rational to want in an object of a certain type for talk of the goodness of objects of that type with those properties. The irst stage of deinition says that “A is a good X if and only if A has the properties . . . which it is rational to want in an X, given what X’s are used for, or expected to do, and the like” (TJ 350–351). Next, “A is a good X for K (where K is some person) if and only if A has the properties which it is rational for K to want in an X, given K’s circumstances, abilities, and plan of life, and therefore in view of what he intends to do with an X” (TJ 351). The first stage, then, deines the goodness of some object in terms of the properties it is rational to want in that object, given the purposes for which objects of its kind are typically used. The next stage relativizes the idea of the good to a particular person’s wants and ends.