In Rawls’s very first statement of his two principles of justice, the second principle says that social and economic inequalities are to be arranged so that “it is reasonable to expect that they will work out for everyone’s advantage, and provided the positions and ofices to which they attach . . . are open to all” (“Justice as Fairness” [1958] in CP 48). In subsequent writings in the 1960s and in his initial statement of the two principles in A Theory of Justice (TJ 53) the core formulation of the second principle, requiring “everyone’s advantage” and positions “open to all,” is retained.

Rawls recognizes the key terms, “everyone’s advantage” and “open to all” (or “equally open”), require explication. He provides this by developing (TJ §§12 and 13) three different ways to interpret the second principle of justice, and in each of these interpretations the two key terms are linked together. Here he closely follows the pattern set in his important 1968 paper “Distributive Justice: Some Addenda” (CP 158–164).

The first interpretation is called by Rawls the system of natural liberty (a term he takes from Adam Smith). Two distinct themes are involved here. One is that positions are “equally open” where there are no legal or institutional or customary barriers that restrict entry into an occupation to one class or kind of individual and no formal restrictions on the taking of opportunities. The result of ending such restrictions would be “careers open to talents’’; individuals would be free to exercise their talents or seize opportunities up to the limit of their own abilities. This leads directly to the second theme. In a system of natural liberty (assuming a self-stabilizing open and competitive supply–demand free market system), the ideal result would be a recurring tendency toward pareto-optimal efficiency in the exchange of goods and services.