Agency and Deontic Logic

Abstract

Develops deontic logic against the background of a rigorous theory of agency in branching, or indeterministic, time. It is often assumed that the notion of what an agent ought to do can be identified with that of what it ought to be that the agent does. The book provides a framework in which this assumption can be formulated precisely and shown to be mistaken. In its place, it offers an alternative account of what agents ought to do that relies on an analogy between action in indeterministic time and choice under uncertainty, as it is studied in decision theory. This alternative account is then related to issues involving conditional obligation, group obligation, act utilitarianism, and rule utilitarianism.

Perspectival Act Utilitarianism

“…This problem was first pointed out in my [14], but here I address what I now think of as a mistake in that treatment. In that earlier book, in order to explain our conflicting judgments about right actions, I set out two substantially different accounts of the notion, which I labeled as the "dominance" and "orthodox" accounts.…”

“…The constraints can be found in my [14], and are described in authoritative detail in Belnap, Perloff, and Xu [3].…”

“…In my [14], I adopted a strategy, which still seems reasonable to me, and which I review here, of first introducing a concept of conditional optimality, and then conditionalizing on a proposition that represents the agent's circumstances.…”

“…With these concepts before us, we can now, as in [14], define a form of act utilitarianism designed to model the orthodox notion found in the work of Gibbard, Sobel, Regan, and others. What the definition tells us, then, is simply that the action K is right at the index m/h whenever K is optimal under the condition specified by the state containing the history h.…”

“…Suppose that, looking back at the situation from some later moment belonging to h 4 -perhaps while The situation pictured in Figure 7, then, seems to support two different evaluations of the agent's decision not to swerve-that it was wrong, or right-which can then be captured by our two theories of right and wrong actions, orthodox and dominance. This idea, originally set out in [14], of analyzing examples of this kind by appeal to two separate utilitarian theories carries some distinct advantages. It does not force us into the artificial position of classifying the agent's action either as unequivocally right or as unequivocally wrong, ignoring the pull of the opposite intuition.…”