 In the not so recent past it might have been asked why a theory of social institutions has, or ought to have, any philosophical interest; why not simply leave theories of institutions to the theoretical sociologists? However, in recent years philosophers have addressed a variety of ontological, explanatory, normative and other theoretical issues concerning social institutions (Searle 1995, 2007 and 2010; Tuomela 2002; Miller 2010; Epstein 2015; Guala 2016; Ludwig 2017). Of particular importance is the work of John Searle (1995; 2010). One source of the impetus for this has been recent philosophical work on social action and social forms more generally (Gilbert 1989; Searle 1990); Tuomela 2007; Schmid 2009; Miller 2001; Bratman 2014; Tollefsen 2015; Ludwig 2016). Another source is the recognition that a good deal of normative work on social justice, political philosophy and the like presupposes an understanding of social institutions. For instance, philosophers, such as John Rawls (1972), have developed elaborate normative theories concerning the principles of justice that ought to govern social institutions.  Yet they have done so in the absence of a developed theory of the nature and point of the very entities (social institutions) to which the principles of justice in question are supposed to apply. Surely the adequacy of one’s normative account of the justice or otherwise of any given social institution, or system of social institutions, will depend at least in part on the nature and point of that social institution or system. Thus distributive justice is an important aspect of most, if not all, social institutions; the role occupants of most institutions are the recipients and providers of benefits, e.g. wages, consumer products, and the bearers of burdens, e.g. allocated tasks and, accordingly, are subject to principles of distributive justice. Moreover, arguably some institutions, perhaps governments, have as one of their defining ends or functions, to ensure conformity to principles of distributive justice in the wider society. However, distributive justice does not appear to be a defining feature, end or function of all social institutions. By this I do not mean that some social institutions are unjust and, for instance, exist in practice to serve narrow economic or other special interests (Marx 1867; Habermas 1978; Honneth 1995); though clearly many are. Rather I am referring to the fact that a number of social institutions, such as the so-called Fourth Estate and the university, are arguably not defined—normatively speaking—in terms of justice, but rather by some other moral value(s), e.g. truth (Ostrom 2005; Miller 2010). 