 Supposing institutions, in particular, are collective agents there remains the question of the relationship between these collective agents and their human members. The favoured relationship, e.g. by List and Pettit, is that of supervenience. Epstein has provided detailed arguments against the supervenience thesis. He distinguishes between what he refers as the grounding and the anchoring of social phenomena, including institutions and institutional objects, and utilizes H. L. A. Hart’s distinction between primary rules and secondary rule in doing so (Hart 1961). Roughly speaking, primary rules directly govern the behaviour of citizens, e.g. laws against murder. Secondary rules determine what the primary rules are, e.g. the legislative processes for enacting primary rules. According to Epstein, the grounds of a primary rule against murder consist of facts such as intentional killing, whereas secondary rules, e.g. the legislative enactment process, would anchor the primary rule. Let us now see how this grounding/anchoring distinction works by way of the example of the Supreme Court of the US. According to Epstein (2015: 223), the fact that the Supreme Court issues a particular opinion is grounded in facts such as that its members voted in particular ways. Moreover, their powers, e.g. to vote, are anchored in part by the US Constitution and the Judiciary Acts (which established the US courts). However, says Epstein, some grounding facts are external to facts about the members of the institution in question, e.g. external to facts about the justices of the Supreme Court.  Therefore, the actions of a group depend on more than the actions of the members of the group. For instance, the issuance of an opinion by the Supreme Court depends on more than the votes and other actions of the justices of the Supreme Court, it also depends on the constraints on their actions (Epstein 2015: 227), e.g. constraints imposed by, i.e. anchored in, the US Constitution and the Judicial Acts. Epstein takes this dependence of the actions of the Supreme Court on external facts, and specifically the actions of persons other than the members of the Supreme Court, to undermine the supervenience claim. This is plausible. However, since the argument at this point simply assumes that the Supreme Court per se performs actions, it does not demonstrate that the actions of the Supreme Court are not simply the actions of the members of the Supreme Court. For if we assume contra Epstein that the Supreme Court per se is not an agent and does not perform actions, then his argument merely demonstrates what is clearly correct, namely, that the actions of the members of the Supreme Court are to some extent dependent on the actions of persons other than the members of the Supreme Court, e.g. the framers of the US Constitution and of the Judicial Acts. Indeed, arguably, it is the view that institutions per se are agents that is the root of the problem and the difficulties identified by Epstein that arise from positing the supervenience relation merely symptoms. For if institutions are not agents per se and, therefore, do not perform actions and are not possessed of mental states, then there is no need to posit this supervenience relation. 