Obligations and Permissions

Utterances and statements that are concerned with obligations and permissions are known as deontic expressions. They can present something of a challenge when it comes to formalising their meaning and behaviour. The content of these expressions can appear to support entailment relations similar to those of classical propositions, but such behaviour can sometimes lead to counter‐intuitive outcomes. Historically, much of the descriptive work in this area has been philosophical in outlook, concentrating on questions of morality and jurisprudence. Some additional contributions have come from computer science, in part due to the need to specify normative behaviour. There are a number of formal proposals that seek to account for obligations and permissions, such as Standard Deontic Logic . In the literature, there has also been discussion of various conundrums and dilemmas that need to be resolved, such as the Good Samaritan , the Knower , the Gentle Murderer , Contrary to Duty Obligations , Ross's Paradox , Jørgensen's Dilemma , Sartre's Dilemma , and Plato's Dilemma . Despite all this work, there still appears to be no definite consensus about how these kinds of expressions should be analysed, or how all the deontic dilemmas should be resolved. It is possible that obligations themselves, as opposed to their satisfaction criteria, do not directly support a conventional logical analysis. It is also possible that a linguistically informed analysis of obligations and permissions may help to resolve some of the deontic dilemmas, and clarify intuitions about how best to formulate a logic of deontic expressions.