Basic logic for ontic and deontic modalities
Abstract
The difficulty to interpret the iteration of modalities, already ontic and still more deontic, incites to pay attention to the system B of basic modal logic that John L. Pollock proposed in 1967. The Pollock’s system brought all the theses which, in the classical ontic modal systems, from Sl to S5, contain no iteration of the modal functors. With this basic ontic system we characterize a basic deontic system, and a basic ontico-deontic system, the former including all the theses of the first two. Each of the three systems is based axiomatically and assorted with a semantics for which the soundness and the completeness hold