Supererogation and conditional obligation

Philosophical Studies - There are plenty of classic paradoxes about conditional obligations, like the duty to be gentle if one is to murder, and about “supererogatory” deeds beyond the...     

Agential obligation as non-agential personal obligation plus agency

I explore various ways of integrating the framework for predeterminism, agency, and ability in [P. McNamara, Nordic J. Philos. Logic 5 (2) (2000) 135] with a framework for obligations. However, the agential obligation operator explored here is defined in terms of a non-agential yet personal obligation operator and a non-deontic (and non-normal) agency operator. This is contrary to the main current trend, which assumes statements of personal obligation always take agential complements. Instead, I take the basic form to be an agent's being obligated to be such that p. I sketch some logics for agential obligation based on personal obligation and agency, first in a fairly familiar context that rules out conflicting personal obligations (and derivatively, conflicting agential obligations), and then in contexts that do allow for conflicts (of both sorts). Finally, a solution to van Fraassen's puzzle is sketched, and an important theorem is proved.     

Combinations of tense and deontic modality: On the approach to temporal logic with historical necessity and conditional obligation

We consider three infinite hierarchies of what I call “two-dimensional temporal logics with explicit realization operators”, viz. (i) one without historical or deontic modalities, (ii) one with historical but without deontic modalities, and (iii) one with historical and with dyadic deontic modalities for conditional obligation and permission. Sound and complete axiomatizations are obtained for all three hierarchies relative to a simplified version of the finite co-ordinate-system semantics given for so-called T × W logic of historical necessity in [L. Åqvist, The logic of historical necessity as founded on two-dimensional modal tense logic, J. Philos. Logic 28 (1999) 329–369].     

Agency and obligation

The purpose of this paper is to explore a new deontic operator for representing what an agent ought to do; the operator is cast against the background of a modal treatment of action developed by Nuel Belnap and Michael Perloff, which itself relies on Arthur Prior's indeterministic tense logic. The analysis developed here of what an agent ought to do is based on a dominance ordering adapted from the decision theoretic study of choice under uncertainty to the present account of action. It is shown that this analysis gives rise to a normal deontic operator, and that the result is superior to an analysis that identifies what an agent ought to do with what it ought to be that the agent does.     

Prima facie obligation

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.     

Fairness and political obligation

Abstract

In this paper I offer a limited defence of “fairness” or “fair play” arguments for political obligation by focussing on one important critique of such arguments, that offered by A. John Simmons. I isolate Simmons’s concentration on the idea of “accepting” benefits and argue that, among other difficulties, his criteria for when we can be said to accept a benefit from our political communities are too restrictive. While the scope of the discussion is narrow, I try to sketch ways in which the failings of Simmons’s critique are symptomatic of deeper problems with his libertarian approach.     

Notes on conditional logic

This paper consists of some lecture notes in which conditional logic is treated as an extension of modal logic. Completeness and filtration theorems are provided for some basis systems. These notes were originally drafted for a course given at the University of Auckland in 1987 (Philosophy 29.308). The work reported in Section 5 is due to Michael Strevens, who took the course and presented his conception of a filtration in a term paper [5]. The author wishes to thank Strevens for many stimulating discussions and for permission to include his results here     

Shafer on conditional probability

Journal of Philosophical Logic -     

A logic of comparative obligation

Normal systems of modal logic, interpreted as deontic logics, are unsuitable for a logic of conflicting obligations. By using modal operators based on a more complex semantics, however, we can provide for conflicting obligations, as in [9], which is formally similar to a fragment of the logic of ability later given in [2], Having gone that far, we may find it 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. This paper, building on the formalism of the logic of ability in [2], provides a complete and decidable system for such a language.