A Fine-Grained Analysis of Normative Language and Its Logic

Normative reasoning is reasoning involving normative notions, both deontic, such as obligations, permissions, and evaluative, such as what is good, bad, right. Standard accounts of normative reasoning, based on normal modal logic, are too coarse-grained to be useful, also because they allow for absurd consequences from perfectly legitimate premises (e.g. If you ought to send a letter, then you ought to send a letter or burn it). I propose to study and construct logics for normative reasoning which are fine-grained enough to be useful to real-world agents; logics, for instance, which eschew irrelevant or absurd conclusions. The logics I propose are for deontic notions, for evaluative notions, and for normative reasons, and have in common the fact that they are hyperintensional and use truthmaker semantics.