On Prima Facie Obligations and Nonmonotonicity

• Published in: Journal of philosophical logic Vol. 36; no. 5; pp. 599 - 604
• Main Author: Hurtig, Kent
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.10.2007; Springer Nature B.V
• Subjects: Defeasible reasoning; Deontic logic; Ethics; Etik; Filosofiämnen; Historisk-filosofiska ämnen; History and philosophy subjects; HUMANIORA och RELIGIONSVETENSKAP; HUMANITIES and RELIGION; Logic; Logik; monotonicity; Nonmonotonic logic; Normativity; Obligation; ought; overridingness; Philosophers; Philosophical logics. Philosophy of language; Philosophy; Philosophy subjects; Practical philosophy; Praktisk filosofi; Prima facie duties; Promises; Reasoning; reasons; Taxpaying; Philosophical Logic
• ISSN: 0022-3611; 1573-0433; 1573-0433
• DOI: 10.1007/s10992-007-9056-0

# Springer 2007 Journal of Philosophical Logic (2007) 36: 599Y604 DOI: 10.1007/s10992-007-9056-0 KENT HURTIG ON PRIMA FACIE OBLIGATIONS AND NONMONOTONICITY Received 28 October 2005 In their introduction to Defeasible Deontic Logic1 Donald Nute and Xiaochang Yu write: A defeasible deontic logic may not only solve some of the familiar paradoxes of deontic logic, but may actually be attractive to moral philosophers, jurists, and others who would seem to be the natural clients of the deontic logician.2 I agree that a defeasible (or nonmonotonic) deontic logic may help solve some of the so-called paradoxes of deontic logic. Strictly speaking, pro tanto reasons are probably best understood as relations, the relata of which are (at least) facts, agents and actions: the fact that you will disappoint her if you 8 gives you a reason not to 8.Reasons may of course be outweighed,9, or defeated, or overridden, by other reasons (or sets of reasons) with respect to what ought to be done Y or, as it is sometimes put, with respect to what ones obligation or duty proper is Y but this is not the same kind of defeasibility which is associated with nonmonotonicity. Whether or not reasons for action are themselves defeasible (suitably construed) is a substantive issue which must be settled in the theory of practical reason; it is not something that can be settled (or even motivated by) the observation that there is some sort of overridingness going on in normative reasoning.11 To repeat: reasons are indeed defeasible by other reasons with respect to what ought (overall) to be done, but this does not mean that a conditional like (3) If the fact that F gives A a reason (gives A a prima facie obligation) to 8, then F gives A a reason (gives A a prima facie obligation) to 8. doesnt bind, or that it should be subject to a nonmonotonic analysis. In what follows, I shall speak only of reason(s) and take pro tanto as read. 12 We may also need to add a third conjunct to the antecedent: and it is not the case that A has some reason not to 7 which is such that its strength is equal to the reason he has to 7. Because if the reasons for and against 7-ing are equally strong, it is far from clear that A ought to 7.