A dynamic semantics for iffy oughts offers an attractive alternative to the folklore that Chisholm's paradox enforces an unhappy choice between the intuitive inference rules of factual and deontic detachment. The first part of the story told here shows how a dynamic theory about ifs and oughts gives rise to a nonmonotonic perspective on deontic discourse and reasoning that elegantly removes the air of paradox from Chisholm's puzzle without sacrificing any of the two detachment principles. The second part of the (...) story showcases two bonus applications of the framework suggested here: it offers a response to Forrester's gentle murder paradox and avoids Kolodny and MacFarlane's miners paradox about deontic reasoning under epistemic uncertainty. A comparison between the dynamic semantic proposal made in this paper and a more conservative approach combining a static semantics with a dynamic pragmatics is provided. (shrink)

An argument against the bias towards the near; how a defence of temporal neutrality is not a defence of S; an appeal to inconsistency; why we should reject S and accept CP.

This paper develops an informal semantics for 'ought to be' and 'ought to be given...' and argues for its plausibility. A feature of the semantics is that it invalidates 'if a entails b, And o(a), Then o(b)' and 'if o(a) & o(b), Then o(a&b)', While validating detachment for conditional obligation.

We argue that desire is an attitude that relates a person not to one proposition but rather to two, the first of which we call the object of the desire and the second of which we call the condition of the desire. This view of desire is initially motivated by puzzles about conditional desires. It is not at all obvious how best to draw the distinction between conditional and unconditional desires. In this paper we examine extant attempts to analyse conditional (...) desire. From the failures of those attempts, we draw a moral that leads us to the correct account of conditional desires. We then extend the account of conditional desires to an account of all desires. We attempt to explain the distinction between intrinsic and extrinsic desire in light of our account of desire. We show how to use our account to solve Wollheim’s paradox of democracy and to save modus ponens. Finally, we extend the account of desire to related phenomena, such as conditional promises, intentions, and commands. (shrink)

We investigate under what conditions contrary-to-duty (CTD) structures lacking temporal and action elements can be given a coherent reading. We argue, contrary to some recent proposals, that CTD is not an instance of defeasible reasoning, and that methods of nonmonotonic logics are inadequate since they are unable to distinguish between defeasibility and violation of primary obligations. We propose a semantic framework based on the idea that primary and CTD obligations are obligations of different kinds: a CTD obligation pertains to, or (...) pre-supposes, a certain context in which a primary obligation is already violated. This framework is presented initially as an extension of Standard Deontic Logic (SDL), a normal modal logic of type KD, and is illustrated by application to a series of examples. The concluding section is concerned with some resemblances between CTD and defeasible reasoning. We show first that the SDL-based framework contains a flaw and must be adjusted. A discussion of possible adjustments, including an alternative treatment in terms of a preference-based semantics, reveals difficulties that are reminiscent of problems in defeasible reasoning and intensional accounts of defeasible conditionals. (shrink)