 Roughly speaking, an institution that is an organisation or system of organisations consists (at least) of an embodied (occupied by human persons) structure of differentiated roles (Miller 2010; Ludwig 2017). (Naturally, many institutions also have have additional non-human components, e.g. buildings, raw materials.) These roles are defined in terms of tasks, and rules regulating the performance of those tasks. Moreover, there is a degree of interdependence among these roles, such that the performance of the constitutive tasks of one role cannot be undertaken, or cannot be undertaken except with great difficulty, unless the tasks constitutive of some other role or roles in the structure have been undertaken or are being undertaken. Further, these roles are often related to one another hierarchically, and hence involve different levels of status and degrees of authority. Finally, on teleological and functional accounts, these roles are related to one another in part in virtue of their contribution to (respectively) the end(s) or function(s) of the institution; and the realisation of these ends or function normally involves interaction among the institutional actors in question and external non-institutional actors. (The assumption here is that the concept of an end and of a function are distinct concepts. On some accounts, function is a quasi-causal notion (Cohen 1978 Chapter IX), on others it is a teleological notion, albeit one that does not necessarily involve the existence of any mental states (Ryan 1970 Chapter 8)). The constitutive roles of an institution and their relations to one another can be referred to as the structure of the institution. 