Rawls’s account of institutions has features that are inspired both by Hart’s work on law as a social practice (Hart 1994) and by Searle’s account of speech acts (Searle 1969). He understands institutions as being “public systems of rules which deine ofices and positions with their rights and duties, powers and immunities” (TJ 47). Such rules deine certain kinds of actions as permissible, mandatory, or forbidden, and envisage sanctions when violations occur. In this sense, the game of football is an institution just as much as the American Congress. We can refer to an institution as an abstract object, by describing its rules; said institution then exists, following Hart, when a set of agents actually perform the appropriate actions foreseen by its rules, and mutually understand one another’s conduct as compliance with those rules. This mutual knowledge and publicity are necessary features of institutions. For example, for two people to play the game of chess, it is not suficient that they happen to perform the actions that the game prescribes. Additionally, each of them must also (1) know what the rules of chess are; (2) understand herself and the other player as being engaged in the game of chess according to those rules; (3) know that the other player also has the same knowledge and understanding; and (4) know that the other player knows that she knows this.