  In the first few pages of his 1980 paper, “Models and Reality,” Putnam argues that there is at least one intended model for the language of set theory which satisfies the set-theoretic axiom  V=L.[44]  To show this, Putnam begins by assuming that there are only two things which could play a role in fixing the intended model for set-theoretic language. First, there are what Putnam calls “theoretical constraints.” These include the standard axioms of set theory, as well as principles and theories from other branches of science. Second, there are “operational constraints.” These are just the various empirical observations and measurements that we make in the course of scientific investigation.