Modal Logic as Methodology

In Modal Logic as Metaphysics, Timothy Williamson develops a case for necessitism, the theory that necessarily everything necessarily exists. Williamson’s arguments are primarily contrastive—he contends that a modal logic with necessitist theorems is stronger, simpler, less ad hoc, and supports more true generalizations about metaphysical modality than its contingentist rivals. But Williamson does not present his work as just a sustained objection to contingentism. As he makes clear in the afterword, Williamson also wants to change the way we do modal metaphysics. The prevailing approach to metaphysics is best described as an intuitiondriven methodology. Theories are stated as clearly as possible in any language (typically a combination of English and first-order logic). Their entailments are identified, and intuitions are cited as evidence for or against particular claims of the theories. The goal is to identify the theory that carries the balance of intuitive support. As Lewis describes it: “(when) all the tricky arguments and distinctions and counterexamples have been discovered, presumably we still face the question of which prices are worth paying, which theories are on balance credible, which are the unacceptably counterintuitive consequences and which are the acceptably counterintuitive ones... And if all is indeed said and done, there will be no hope of discovering still further arguments to settle our differences.” If we use the intuition-driven methodology, then necessitists fight an uphill battle. The theory vindicates some intuitions—for example, that we can refer to merely possible objects. But it predicts that one pervasive intuition is wildly mistaken—namely, that objects like the life-sized butter statue of Elvis Presley at the 1997 Iowa State Fair could have failed to exist. When the costs have been tallied, the strength of intuitions about contingent