Cumulativity,Identity and Time in Deontic Logic

Abstract

We first analyse the future-orientated account of conditional obligation as put forth by David Makinson. We show that the introduction of the futurity dimension is not indispensable in the elimination of the identity principle. This leads us to a more general observation. Most systems of dyadic deontic logic either accept both the identity principle and the cumulativity condition, or exclude both. We then develop an account of defeasible conditional obligation based on the ``and next" operator, as a solution to this dilemma.