 Just as semantic doctrines more-or-less related to logical positivism were central to the S-naturalism of Scandinavian Realism, the more recent S-naturalism of writers like David Brink, Michael Moore, and Nicos Stavropoulos is indebted to the revolution in semantics initiated by Hilary Putnam and Saul Kripke known as the “new” or “causal” theory of reference. These latter doctrines are not—yet in any case—museum pieces, so the derived jurisprudential theses are very much live items of debate. Stavropoulos explains the core semantic ideas on which jurisprudential writers draw as follows: