Abstract

It is an appealing idea that deontic modality is a modality of the open future, and that the indeterminacy of the open future is the key, within natural language, to understanding the deontic modal puzzles that form the traditional subject-matter of deontic logic. In this paper, I pull together three well-studied strands of indeterminism—Thomason (1980)’s settledness operator, the modal base of Kratzer (1981, 1991)’s analysis of modals, and Stalnaker (1978)’s notion of diagonal acceptance—to argue for two theses governing a deontic logic for natural language. The first thesis makes a claim about postsemantic truth, and is couched in terms of Stalnaker’s dagger operator. The second concerns what it is for an act to be permissible, when agents exercise partial control over their obligations as well as their bodily movements.