The inferential constraint and if \(\varvec{\phi }\) ought \(\varvec{\phi }\) problem

The standard semantics for modality, together with the influential restrictor analysis of conditionals (Kratzer, 1986, 2012) renders conditional ought claims like “If John’s stealing, he ought to be stealing” trivially true. While this might seem like a problem specifically for the restrictor analysis, the issue is far more general. Any account must predict that modals in the consequent of a conditional sometimes receive obligatorily unrestricted interpretation, as in the example above, but sometimes appear restricted, as in, e.g., “If John’s speeding, he ought to pay the fine.” And the problem runs deeper, for there are non-conditional variants of the data. Thus, the solution cannot lie in adopting a particular analysis of conditionals, nor a specific account of the interaction between conditionals and modals. Indeed, with minimal assumptions, the standard account of modality will render a myriad of claims about what one ought to, must, or may, do trivially true. Worse, the problem extends to a wide range of non-deontic modalities, including metaphysical modality. But the disaster has a remedy. I argue that the source of the problem for the standard account lies in its failure to capture an inferential evidence constraint encoded in the meaning of a wide range of modal constructions. I offer an account that captures this constraint, and show it provides a general and independently motivated solution to the problem.