Shall, Must, May: The Logic of Legal Obligation and Permission

You ought to do something ! The logic of obligation as weakest permission

This paper studies the following interpretation of obligations: A person i ought to do A in a situation S just in case everything else i may (and can) do in S is consistent with A. In such case A can be called the weakest permission that i has in S. We show that, under this interpretation, obligation and permission are not dual notions, and that it gives rise to an interesting interplay between...

An Action-based Logic of Causality, Knowledge, Permission and Obligation 1

The critical properties required of secure systems can vary widely in their nature from application to application. Diierent properties required within the same system can result in interactions that are diicult to understand. In addition, the integration of systems having diierent properties can cause unanticipated interactions. The Critical System Logic (CSL) addresses these problems by provi...

The logic of conditional obligation

The Logic of Permission and Obligation in the Framework of ALX.3: how to avoid the paradoxes of deontic logics

Standard deontic logic features fairly serious socalled “paradoxes” (technically: counterintuitive validities). Much energy in deontic logic has been spendt on avoiding these “paradoxes”. We suggest a reformulation of deontic logic in terms of a multiagent logic, ALX.3, where a “super-agent” (think of a legislature) lays down the law of the land and other agents have to follow its rules. In par...

Conditional Obligation and Positive Permission for Agents in Time

This paper investigates the semantic treatment of conditional obligation, explicit permission (often called positive permission), and prohibition based on models with agents and branched time. In such models branches (rather than moments) are taken as basic, and the branching provides a way to represent the indeterminism which is normally presupposed by talk of free will, responsibility, action...