 The idea that with the development of the sciences over time, theories are converging on (“moving in the direction of”, “getting closer to”) the truth, is a common theme in realist discussions of theory change (for example, Hardin &amp; Rosenberg 1982 and Putnam 1982). Talk of approximate truth is often invoked in this context and has produced a significant amount of often highly technical work, conceptualizing the approximation of truth as something that can be quantified, such that judgments of relative approximate truth (of one proposition or theory in comparison to another) can be formalized and given precise definitions. This work provides one possible means by which to consider the convergentist claim that theories can be viewed as increasingly approximately true over time, and this possibility is further considered in  section 3.4.