In this paper we introduce a new deontic logic P_reD_eL (Predicative Deontic Logic), an extension of the system PD_eL, based upon ideas derived from Meyer. This extension includes the addition of actors and conditions under which an actor executes an action. The addition of actors and conditions allows us to express who has the responsibility to execute an action under which conditions. The system P_reD_eL has been developed to formalize sections in law, especially the Dutch traffic regulation. At the end of hte paper we will see an example of the formalization of the speed-limit of the Dutch traffic regulation.

Keywords: deon94

This paper compares two ways of formalizing deeasible deontic reasoning, both based on the view that the issues of conflicting obligations and moral dilemmas should be dealt with froma a nonmonotonic perspective. The first way is developing a special nonmonotonic logic for deontic statements. This methods turns out to have some limitations, for which reason another approach is proposed, viz. combining an already existing nonmonotonic logic with a deontic logic. As an example of this method the language of Reiter's default logic is extended to include modal expressions, after which the argumentation framework in default logic of Prakken (1993a/b) is used to give a plausible nonmonotonic analysis of conflicting obligations.

Keywords: deon94

This paper investigates under what conditions contrary-to-duty structures lacking temporal elements can be given a coherent reading. A negative result is that methods of nonmonotonic reasoning are inadequate, since they are unable to distinguish between defeasibility and violability of primary obligations. On the positive side, this paper proposes a semantic framework based on the idea that primary and contrary-to-duty obligations are obligations of different kinds, in that they pertain to different contexts. A crucial aspect of this idea is that, although a context may violate some obligations, it should still measure ip to the ideal worlds as much as possible. The framework has many desirable features but it also contains a major flaw. Identification of the source of the problem suggests a similarity between contrary-to-duty reasoning on the one hand and theory revision and defeasible reasoning on the other.

Keywords: deon94

Bureaucratic rules can be modeled using deontic logic and such formalization will facilitate the automation of these rules. Unfortunately, if these rules re not well designed, they can create a form of inconsistency that we call deontic dilemmas. Normally, deontic dilemmas can only be detected when the rules are being applied to some situations. In this paper, we propose the use of a form of plausible reasoning called abduction for detecting potential deontic dilemmas in generated hypothetical scenarios. The goal is to detect these deontic dilemmas in these future scenarios so as to repair the rules before they are used. In addition, we also introduce the notion of contingent abduction that allows abduction to be performed conditionally based on the deontic status. This facilitates the definition and exploration of deontically obedient scenarios as well as scenarios with deontic violations and satisfactions.

Keywords: deon94

Civil procedure turns on acts of claim, concession, denial, and retraction with respect to social commitments: both in the boulomaic-deontic ('demand') and the epistemic-alethic ('assertion') domain. I represent in finite state automat a paradigmatic 2-person binary issue of negotiation about joint commitment. A procedural semantics associates acts one-one with their target states. A denotational semantics for states as vectors of decision-theoretic parameters yields a translation group. Act-types and their transformations are represented by quotient algebras. A functor to the familiar Deontic Square reveals differences in characteristic order relations of preference and entailment and raises questions about models of deontic and assertion logics.

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Sir David Ross introduced prima facie duties, or acts with a tendency to be duties proper. He also spoke of general prima facie principles, which attribute to acts having some feature the tendency to be a duty. Like Utilitarians from Mill to Hare, he saw a role for these principles in the epistemology of duty: in the process by means of which, in any given situation, a moral code can help us find out what we ought to do. After formalizing general prima-facie principles as universally quantified conditionals I will show how seeming duties can be detached from them. There will be examples involving lies; burnt offerings, and the question of whether to have a napkin on your lap while eating asparagus. They will illustrate the defeasibility of this detachment, how it can lead into dilemmas, and how general prima-facie principles are overridden by more spcific ones.

Keywords: deon94

On the traditional deontic framework, what is required (what morality demands) and what is ideal (what morality recommends) can't be distinguished and hence they can't both be represented. Although the morally optional can be represented, the supererogatory, one of its proper subclasses, cannot be. The morally indifferent, another proper subclass of the optional-one obviously disjoint from the supererogatory-is also not representable. Similarly for the permissibly supoptimal and the morally significant. Finally, the minimum that morality allows finds no place in the traditional scheme. So the traditional scheme is radically incomplete. With a focus on the question, "What would constitute a hospitable logical neighborhood for the concept of supererogation?", I present and motivate an enriched logical and semantic framework for representing all these concepts of common sense morality.

Keywords: deon94

We will show that formal theories about the deontic status of actions can quite well be formulated in terms of the standard two-sorted first-order extensional predicate calculus. The resulting logical system are much easier to implement than the modal accounts of the deontic logic of action which are currently popular. A prototype implementation of a first-order extensional deontic logic of action (R.M. Lee's expert shell DX) is briefly described.

Keywords: deon94

This paper addresses the problem of automated deduction for such logics. For many of them, we solve the problem by exhibiting a sound and complete translation from non-normal modal logics into normal multi-modal logics for which efficient proof methods have been devised in the last years. This allow the possibility of a real use of such logics in the field of Deontic Logic.

Keywords: deon94

The objective of this paper is to propose a new semantics for a class of normative positions that applies deontic operators to descriptions of possible act-positions. This semantics is based on the concept of role which represents a behavior an agent is authorized to play. Within this new semantics, we investigate several deontic problems such as the treatment of Chisholm's Paradox, moral dilemmas and defeasibl reasoning.

Keywords: deon94

In this paper, we give a solution to the Free Choice Paradox. This is done in two stages. First, we have a close look at the logical interpretation of the natural language statements that lead to the paradox. This leads to making the important distinction of permitting an action in isolationor permitting it in combination with some or any other action, i.e., in a certain context. This distinction is made formal by the introduction of a new operator on actions, which forces them to be performed in isolation. With this distinction made clear it is possible to give a "new" stronger definition for the permission operator, which solves the Free Choice Paradox and which does not lead to any new inconsistencies or paradoxes.

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The paper discusses the potential value of a deontic approach to database specification. More specifically, some different types of integrity constraints are considered and a distinction is drawn between necessary ("hard") and deontic ("soft") constraints. Databases are compared with other normative systems. A deontic logic for database specification is proposed, and is compared to some other systems of deontic logic. The recovery problem is discussed in the context of this logic. The limitations of the proposed logic and possible modifications and extensions of it are analyzed.

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This paper presents a nonmonotonic deontic logic based on commonsense entailment. It establishes criteria a successful account of obligation should satisfy, and develops a theory that satisfies them. The theory includes two conditional notions of prima facie obligation. One is constitutive; the other is epistemic, and follows nonmonotonically from the constitutive notion. The paper defines unconditional notions of prima facie obligation in terms of the conditional notions.

Keywords: deon94

Keywords: deon94

Normal systems of modal logic, interpreted as deontic logics, are unsuitable for a logic of conflicting obligations. By using modal operators based on a a more complex semantics, however, we can provide for conflicting obligations, as in van Fraassen [1973] and Brown [1988]. Having gone that far, it becomes desirable to be able to express and consider claims about the comparative strengths, or degrees of urgency, of the conflicting obligations under which we stand. Thsi paper, building on the logic of ability in Brown [1988], provides a decidable and complete system for such a language.

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