Dynamic Foundations for Deontic Logic

Lecture Notes in Computer Science, 2010

Normative sentences can be used to change or to describe the normative system, known as prescriptive and descriptive obligations respectively. In applications of deontic logic it is important to distinguish these two uses of normative sentences. In this paper we show how they can be distinguished and analysed in a dynamic epistemic deontic logic.

Normative Multi-agent …, 2007

The paper discusses ten philosophical problems in deontic logic: how to formally represent norms, when a set of norms may be termed 'coherent', how to deal with normative conflicts, how contraryto-duty obligations can be appropriately modeled, how dyadic deontic operators may be redefined to relate to sets of norms instead of preference relations between possible worlds, how various concepts of permission can be accommodated, how meaning postulates and counts-as conditionals can be taken into account, and how sets of norms may be revised and merged. The problems are discussed from the viewpoint of input/output logic as developed by van der Torre & Makinson. We argue that norms, not ideality, should take the central position in deontic semantics, and that a semantics that represents norms, as input/output logic does, provides helpful tools for analyzing, clarifying and solving the problems of deontic logic.

1981

In a recent paper, Sven Danielsson argued that the 'original paradoxes' of deontic logic, in particular Ross's paradox and Prior's paradox of derived obligation, can be solved by restricting the modal inheritance rule. I argue that this does not solve the paradoxes.

Deontic conflicts pose an important challenge to deontic logicians. The standard account —standard deontic logic, SDL— is not apt for addressing this challenge since it trivializes conflicts. Two main stratagems for gaining conflict-tolerance have been proposed: to weaken SDL in various ways, and to contextualize the reign of SDL to consistent subsets of the premise set. The latter began with the work of van Fraassen and has been further developed by Horty. In this paper we characterize this second ap- proach in general terms. We also study three basic ways to contextualize SDL and supplement each of these with a dynamic proof theory in the framework of adaptive logics.

2008

Ratio Juris, 2002

A recent series of papers, sparked off by a note by Robert Walter (1996), has rekindled the debate over the possibility of creating a logic of normative concepts. The debate correctly centres on ways in which Jørgensen’s dilemma might be resolved (Jørgensen 1937–8), since a means of resolving that dilemma is the only apparently available way in which to establish that a logic of norms is possible. Two separate questions require answers: (i) what is the correct way in which to regard Jørgensen’s dilemma; and (ii) how should one face that dilemma? I shall argue that traditional responses to the first question are inadequate, and I shall then try to expose as flawed two recent attempts to resolve the dilemma. Finally, I shall relate my conclusions in the earlier part of the paper to the wider question of whether a logic of normative concepts is, after all, a possibility.

1998

In this paper we propose the deontic logic dus, that formalizes reasoning about prescriptive obligations in update semantics. In dus the definition of logical validity of obligations is not based on truth values but on action dynamics. You know the meaning of a normative sentence if you know the change it brings about in the betterness relation of anyone who is subjected to the news conveyed by it.

Abstract. This paper looks at deontic logic as resulting from both a betterness ordering on states (ie, a 'deontic preference') and a priority ordering on properties (ie, a 'law'explicitly representing a standard of behavior). The correspondence between these two orderings offers a rich perspective from which to look at deontic scenarios and puzzles, and in particular at contrary-to-duties.

A. Introduction. Two key concepts and three perspectives in deontic logic. Situation, agency and agent oriented deontic theories. B. Concept of norm and its structure revisited. Norms as atomic and molecular entities. C. Two approaches to deontic logic: deterministic, focusing on alethic \ deontic regularities, and indeterministic, viewing agentive choice and alternative lines of behavior. D. Conclusion. Three faces of deontic logic pursue different perspective of normative codes' analysis, reasoning about norms and agentive behavior with preferences \ priorities accordingly.

Filosofiska Notiser, 2019

This position paper aims to explore some preliminary suggestions to develop a theory of deontic modalities under a generic understanding. I suggest, for instance , that a sentence such as 'Everyone ought to pay taxes' is true just in case the generic (deontically relevant) individual pays taxes. Different degrees of generic-ity are explored, without assuming too much about a specific theory of genericity. I argue that such an analysis captures our intuitions about exceptions and the general character of deontic claims better than classical approaches based on possible-world semantics and than defeasibility-based approaches, while remaining within a broadly deductive framework.