¹ Kant, Immanuel, Groundwork for the Metaphysics of Morals (1785), ed. Hill, Thomas E. Jr., trans. Zweig, Arnulf (Oxford: Oxford University Press, 2002), esp. p. 222n. (Akademie edition, vol. 4: 421n.)Google Scholar. Below I note some departures from Kant's account, along with other interpretations of imperfect obligation.

² This view emerges in Charles Larmore, “Reflection and Morality,” elsewhere in this volume. Cf. also the “motivation requirement” put forth as a widely accepted starting-point in Wallace, R. Jay, “Three Conceptions of Rational Agency,” Ethical Theory and Moral Practice 2, no. 3 (1999): 217–42, at pp. 217–18CrossRefGoogle Scholar; and the account of a similar view as granted by all parties to the current debate about reasons, in Cullity, Garrett and Gaut, Berys, “Introduction,” in Cullity and Gaut, eds., Ethics and Practical Reason (Oxford: Clarendon Press, 1997), 1–27, at p. 3Google Scholar.

³ Note that “critical,” as I use the term, implies no reference to Kant's Critiques; cf. the notion of a “critical conception of practical reason,” in O'Neill, Onora, “Vindicating Reason,” in Guyer, Paul, ed., A Cambridge Companion to Kant (Cambridge: Cambridge University Press, 1992)Google Scholar. My plural term “practical reasons” refers to particular considerations for or against action, whereas “practical reason” in the singular, without the indefinite article, refers to a faculty of the mind or a system of norms (sometimes capitalized as “Reason”).

⁴ See my “Practical Reasons and Moral ‘Ought’,” in Schafer-Landau, Russ, ed., Oxford Studies in Metaethics, 2 (Oxford: Oxford University Press, 2007), 172–94Google Scholar. “Discounting” is sometimes used more broadly, to cover any reduction in the weight assigned to a reason, on the model of the temporal “discount rate” for value, as in Ainslie, George, Picoeconomics: The Strategic Interaction of Successive Motivational States within the Person (Cambridge: Cambridge University Press, 1992)Google Scholar. As I use the term, discounting might be seen as the limiting case of this broader notion, with weight reduced to zero.

⁵ For utilitarian arguments requiring maximal contribution to famine relief, see esp. Singer, Peter, “Famine, Affluence, and Morality,” Philosophy and Public Affairs 1, no. 1 (1972): 229–43Google Scholar; and Unger, Peter, Living High and Letting Die: Our Illusion of Innocence (New York: Oxford University Press, 1992)Google Scholar. Kant's insistence on doing as much as we can surfaces, e.g., in his application of the formula of humanity to the duty to aid those in need (see Kant, Groundwork, 231 [4: 430]). The point of imperfect duties, on his account, is apparently just to eliminate the possibility of conflicting obligations.

⁶ Cf. Chisholm, Roderick M., “Supererogation and Offense: A Conceptual Scheme for Ethics,” Ratio 5, no. 1 (1963): 1–14Google Scholar.

⁷ For some other attempts to capture optional reasons, see Raz, Joseph, Engaging Reason: On the Theory of Value and Action (Oxford: Oxford University Press, 1999), 90–117Google Scholar; Dancy, Jonathan, “Enticing Reasons,” in Wallace, R. J., Pettit, P., Scheffler, S., and Smith, M., eds., Reason and Value: Themes from the Moral Philosophy of Joseph Raz (Oxford: Oxford University Press, 2004), 91–118Google Scholar; and Gert, Joshua, Brute Rationality: Normativity and Human Action (Cambridge: Cambridge University Press, 2004), esp. 19–39 and 62–84CrossRefGoogle Scholar.

⁸ Cf. Raz, Joseph, Practical Reason and Norms (Princeton, NJ: Princeton University Press, 1990)Google Scholar—though Raz's own account of optional reasons in Engaging Reason rests, instead, on appeal to the incommensurability of first-order reasons.

⁹ See Scanlon, T. M., What We Owe to Each Other (Cambridge, MA: Harvard University Press, 1998), 50–55Google Scholar.

¹⁰ See my “Practical Reasons and Moral ‘Ought’.”

¹¹ See Gert, Brute Rationality, e.g., p. 137.

¹² It also might be said to confer merit on the act, and thereby on the agent, to accommodate the notion of supererogation on the kind of account offered by Terry Horgan and Mark Timmons, “Untying a Knot from the Inside Out: Reflections on the ‘Paradox’ of Supererogation,” elsewhere in this volume.

¹³ One might think my reason for action in such a case would offer a criticism of failure to act, e.g., that a certain potential aid recipient will suffer unless I aid him. But note that this criticism is not really applicable unless no one else is in a position to alleviate the suffering in question. Strictly, the criticism applies to the surrounding community, or to some collective body including myself, which may indeed be subject to requirements in such cases, as will be evident in my later discussion of political issues.

¹⁴ Cf. the accounts of moral obligation in John Skorupski, “Moral Obligation, Blame, and Self-Governance,” and Stephen Darwall, “‘But It Would Be Wrong’,” both elsewhere in this volume. But I would not make the link to emotional blame or other reactive attitudes an explicit part of the definition of moral obligation, if pinning down the relevant sort of practical criticism can do the job. It is essentially criticism that tends to make one unworthy of others' personal regard, or of relationship with others.

¹⁵ For less everyday examples, cf. esp. the case of Paul Gauguin's pursuit of his art by leaving his family and moving to Tahiti, discussed in Williams, Bernard, “Moral Luck,” in Williams, , Moral Luck (Cambridge: Cambridge University Press, 1982), 20–39Google Scholar; and other cases discussed in R. G. Frey, “Goals, Luck, and Moral Obligation,” elsewhere in this volume.

¹⁶ I owe this suggestion to Michael Weber.

¹⁷ Cf. Darwall's account of what he calls “impersonal” reasons in “‘But It Would Be Wrong’.” The term derives from P. F. Strawson's treatment of reactive attitudes in Strawson, , “Freedom and Resentment,” Proceedings of the British Academy 48 (1962): 1–25Google Scholar, where it indicates that an attitude is not a reaction just to a slight to oneself. In application to standpoints of criticism, however, “impersonal” suggests independence of persons generally. I want to distinguish moral reasons from others, such as aesthetic reasons, that might be thought to rest on criticism from an impersonal standpoint. “Interpersonal,” in any case, seems a better fit with the interpretation of moral obligation in terms of “second-personal” demands that Darwall advocates, in an account with which I am broadly in sympathy.

¹⁸ See Kant, Immanuel, The Metaphysics of Morals (1797), trans. Gregor, Mary (Cambridge: Cambridge University Press, 1991)Google Scholar, for the treatment of imperfect duties as requiring direct concern for the beneficiary (which for Kant does not entail undergoing a feeling, but just the adoption of an end). I note that John Rawls also holds that duties of virtue include perfect duties that require action for the right reasons; see Rawls, , Lectures on the History of Moral Philosophy (Cambridge, MA: Harvard University Press, 2000)Google Scholar.

¹⁹ See Mill, John Stuart, Utilitarianism (1863) (Oxford: Oxford University Press, 1998), 94Google Scholar.

²⁰ See Nagel, Thomas, “Justice and Nature,” Oxford Journal of Legal Studies 17, no. 2 (1998): 303–21CrossRefGoogle Scholar. I should note that my ensuing remarks were written before the various economic disasters of September 2008. I am reminded of a fortune cookie I once got: “Today's philosophy is tomorrow's common sense.”

²¹ Philip Pettit has done systematic work along these lines. See, e.g., Pettit, , “Responsibility Incorporated,” Ethics 117, no. 1 (2007): 171–201CrossRefGoogle Scholar.

²² Proximity affects the stringency of duty, including imperfect duty, in part by helping to set a threshold of minimally adequate virtue: unresponsiveness to perceptible suffering on the part of others is, in general, a worse trait than ignoring distant suffering. Cf. Singer, “Famine, Affluence, and Morality,” which denies the relevance of distance, along with degrees of bindingness of obligation.

²³ This is my restatement of a suggestion made by Christopher Morris, to whom I owe the analogy that follows.

²⁴ In addition to my own account here in terms of optional reasons, see the argument in Lauren Fleming, “Imperfect Duties, Moral Latitude, and Constructing Moral Agency” (unpublished) that the “strong latitude” involved in imperfect obligations is essential to self-definition and responsible moral agency.

²⁵ Cf. Raz, Engaging Reason, 102–4; and Gert, Joshua, “Normative Strength and the Balance of Reasons,” Philosophical Review 116, no. 4 (2007): 533–62CrossRefGoogle Scholar, for alternative arguments based on comparison of the two reasons in terms of a univocal measure of strength.

²⁶ See esp. my Practical Guilt (Oxford: Oxford University Press, 1995)Google Scholar. Let me thank Bruce Langtry for pressing this objection in discussion.

²⁷ I argue this in terms of discounting in my essay “Craving the Right: Emotions and Moral Reasons,” in C. Bagnoli, ed., Morality and the Emotions (Oxford: Oxford University Press, forthcoming).

²⁸ See my “Guilt and Virtue,” Journal of Philosophy 91, no. 2 (1994): 57–70CrossRefGoogle Scholar. Acting on a requirement to feel an emotion would depend on some degree of control over what we feel, but on that point see my “Emotional Strategies and Rationality,” Ethics 110, no. 3 (2000): 469–87CrossRefGoogle Scholar.

²⁹ Note that not everything we refer to as “setting priorities” involves the sort of discounting of competing concerns that is at issue in my account. Sometimes, “prioritizing” a particular concern just amounts to assigning it priority in our plans to reflect its pre-given weight or importance. I take it that ordinary talk in political contexts of setting social priorities fits this mold and hence is unproblematic on the common conception of reasons as prima facie requirements. In allowing for priority-setting in light of optional reasons, my own account is also meant to accommodate decisions to modify the pre-given weight of one's reasons. I discuss this in application to free will issues in “Reasons, Decisions, and Free Will” (unpublished).