Abstract

Metaphysicians with reductive theories of reality like to say how those theories account for ordinary usage and belief. A typical strategy is to offer theoretical sentences, often called ‘paraphrases’, to serve in place of various sentences that occur in ordinary talk. But how should we measure success in this endeavor? Those of us who undertake it usually have a vague set of theoretical desiderata in mind, but we rarely discuss them in detail. My purpose in this paper is to say exactly what they are, and why. Among the questions I want to address: what counts as an adequate theoretical replacement for an ordinary sentence? On whom does the burden of proof lie when it is unclear whether a theory of reality can provide a true replacement for some ordinary truism? Which ordinary truisms are most important to ‘save’ in this way, and why? What role does the theoretical virtue of simplicity play in this strategy: is the goal to offer simpler replacement sentences, or a simpler recipe for matching them with ordinary claims? Finally, how do recipes of this sort relate to the theories of natural language sought by semanticists? Answering these questions is crucial if we want to get clear on how best to evaluate reductive theories of reality that make use of the ‘paraphrase strategy’.