Abstract

In the first systems of deontic logic obligatoriness, prohibitiveness and permissibility were features of actions. It was a very natural choice, corresponding to the way in which these concepts were used not only in natural language but also in Law and Ethics. It's well known that contemporary systems of deontic logics do not deal with actions any more. They are simply deontic logics of propositions providing for deontic qualification of states of affairs. Such an approach, although might be useful for instance in Computer Science (especially in security applications, where there is a need of expressing that a certain state of machine is, say, permitted and the other is forbidden), is inadequate for modeling norms of Law and Ethics (and possibly norms of many other fields). In this paper the Simple Theory of Norms and Actions (in short: Setna) is proposed. It is inspired by the first deontic logics, i.e. it's deontic operators take names of actions as their arguments. Additionally this theory has as its part a theory of actions which has not been taken into account in deontic logic until now. Enriching deontic theory with a theory of action gives an account for expressing dependencies which hold between the deontic properties and some other properties of actions. For instance Setna states that two actions that cannot be carried out simultaneously in the same situation should not be both regulated as obligatory-an agent would not be able to follow such a law