Two Arguments against Realism

Over the last 20 years or so, Hilary Putnam has developed a series of arguments which use basic theorems of model theory to undermine semantic realism. Here, I discuss two generalizations of these arguments. The first employs some new forms of model theory to generate substantially stronger conclusions than Putnam’s original arguments generated. The second illustrates a method for replacing the model theory in Putnam’s arguments with results from other branches of science—in particular, with results from astronomy. Now, I should say at the outset that neither of these new arguments is supposed to be persuasive: each of them fails, and fails rather badly, when regarded as a serious objection to realism. Nevertheless, the arguments serve three purposes. First, the parallels between my new arguments and Putnam’s original arguments help to highlight what’s really going on in the latter, and the obvious flaws in my arguments help to isolate the corresponding flaws in Putnam’s arguments. Second, these new arguments expose the inadequacy of several recent defenses of Putnam. (Very roughly, I argue that if these defenses saved Putnam’s arguments, then they would save my arguments as well. But, my arguments are unsalvageable. So, the defenses don’t save Putnam.) Finally, the arguments present a new challenge to Putnam and his defenders: to provide a formulation of the model-theoretic argument which makes that argument seem compelling without doing the same for mine.