 Assume that the conventions, norms or rules in question are social in the sense that they involve the required interdependence of action, e.g. the parties to any given convention, or the adherent to any such norm or rule, conform to (respectively) the convention, norm or rule on the condition that others do. Nevertheless, such interdependence of action is not sufficient for a convention, norm or rule, or even a set of conventions, norms or rules, to be an institution. Governments, universities, corporations etc. are structured, unitary entities. Accordingly, a mere set of conventions (or norms or rules) does not constitute an institution. For example, the set of conventions comprising the convention to drive on the left, the convention to utter, “Australia”, to refer to Australia, and the convention to use chopsticks does not constitute an institution. Accordingly, a problem for atomistic accounts of social institutions is the need to provide an account of the structure and unity of social institutions, and an account that is faithful to atomism, e.g. that the structure is essentially aggregative in nature. On the other hand, ‘atomists’ can obviously help themselves to some notion of a bundle of related conventions or rules. Consider for instance a set of traffic rules, e.g. ‘drive on the left’, ‘do not exceed 35 miles per hour in built up areas’ and so on. Moreover, the ‘bundle’ might include a variety of types of atomistic social forms, e.g. conventions, norms and rules. Guala’s account of institutions (Guala 2016) is a case in point, as we shall see in section 2 below. 