Contrary-to-Duty Imperatives and Conditional Obligation

Abstract

Evidently, deontic logicians agree with Russell; and, as Butler forewarned, morality is thereby menaced. Since its inception a little over fifty years ago with Ernst Mally's Grundgesetze des Sollens: Elemente der Logik des Willens [ 12], deontic logic has been supplied with a wealth of puzzles-usually referred to as deontic paradoxes in the literature.1 True, the majority of these paradoxes evaporate comfortably enough under close scrutiny2 and yet, some-most notably, the Contrary-toDuty Imperative Paradox and certai^n strengthened versions of the Good Samaritan Paradox-threaten recalcitrance. Of these troublesome cases, my plan, in the present paper, is to focus on the Contrary-to-Duty Imperative Paradox; accordingly, I want to examine how various systems of deontic logic fare against this fascinating puzzle. But which systems of deontic logic, exactly? Because of the large number of available systems, together with understandable space limitations, I am forced to be selective. So forced, I have selected three systems for examination; quite by design, each is representative of the by now highly fashionable conditional obligation approach in deontic logic; although, as we shall see, there are important differences among the three. In particular, for our systems of conditional obligation, I will take up van Fraassen's dyadic system [17], Mott's monadic system [13],