On Identifying the Law and Its Supposed Conventional Foundations. A Set-Theory Approach

The paper explores some possible applications of some elementary notions of set theory (such as “intersection”, “union”, and “difference”) to two age- old and intertwined problems of legal philosophy: the identification of law and the rational reconstruction of an ultimate rule of recognition. The main results of the inquiry are the following. (1) Contrary to a widespread view, “law” does not denote a unitary set of rules, but rather a family of sets, the main relations among which are examined in the paper. (2) Contrary to what the strong version of legal conventionalism advocates, there is a conceptual space to regard the rule of recognition as the overlapping of several sets of criteria of identification that are used within a certain community. Amongst other things, this thesis renders the famous Dworkin’s critique against conventionalism harmless.