The current American fad (which I write about critically in Chapter 9 of my forthcoming book) of characterizing legal positivism as the view that “legal facts are grounded in social facts” has as one of its many ironies that the other major 20th-century legal positivist, Hans Kelsen, rejects it (Hart as I argue, does not accept it either, but his view is closer to the misleading formulation). For Kelsen, social facts explain how law comes into being and social facts are relevant to the question of the efficacy of law. But law, for Kelsen, is a system of norms, and these norms are ways of interpreting social/physical facts. This is unsurprising once one remembers that Kelsen’s intellectual culture is a Neo-Kantian one, hostile to all forms of psychologism and any accounts of norms that reduce or explain them in terms of “social” (or psychological) facts.

In the very recent Anglophone literature, it turns out that Kelsen is not a legal positivist since he does not believe the existence and content of law is a matter of social facts. This stands as an indictment of the Anglophone literature, not of Kelsen.