1 For their comments on versions of this paper and discussions about the topics it addresses, I am gratef ul to Larry Temkin, Bill Throop, Jeff McMahon, an anonymous referee for this Journal, and especially John Arthur.

2 Throughout this discussion, I will be taking the word ‘people’ to ref er only to normal adult humans. It is worth mentioning that the consequent modesty of the egalitarian thesis I will be analyzing is significant in several respects. First, the restriction to normal adults insures that the claim that all people are moral equals enjoys particularly broad support, as no controversial Claims about the Standing of, say, human fetuses or humans in vegetative states are being taken for granted. Second, the problems I will raise for this rather weak form of egalitarianism are likely to be only a subset of the problems many actual egalitarians must confront. For instance, most egalitarians believe that infants and young children are owed the same respect and concern as normal adults are. But it is notoriously difficult to justify this claim without committing oneself to extending the same Standing to all sentient animals. And the moral equality of most of the animal kingdom is more than many egalitarians are willing to accept.

3 There is one inf luential analysis of egalitarianism's normative upshot that I will not discuss directly here: namely, that when any two people share the same kind of interest to the same degree, the satisfaction of each of these interests carries equal moral weight. See, for instance, Singer, Peter Practical Ethics, 2nd ed. (Cambridge: Cambridge University Press 1993), 21–5.Google Scholar For reasons I will allude to later, it is not clear that this utilitarian understanding of moral equality is beset by the problems I raise. It is worth remembering, though, that this version of egalitarianism is far weaker than what most egalitarians have in mind, not least because it is compatible with all manner of preferential treatment for those with a greater number of interests. Indeed, it is not even clear that this utilitarian egalitarianism is truly an assertion of the equal moral Standing of individuals, as opposed to the equal Standing of their interests.

4 For a helpful discussion, see Jackson, Frank From Metaphysics to Ethics (Oxford: Clarendon Press 1998), 117–29.Google Scholar

5 While the commitment to supervenience does not entail that there be a Single such difference that figures in the explanation of any difference in Status — a moral property like Standing might be multiply realizable, and thus supervene on a variety of descriptive properties — most contemporary moral theorists hold that there is a Single descriptive ground, or ‘criterion’, for deserving moral Standing. An exception is Warren, Mary Anne who endorses a pluralistic account of moral Standing in her Moral Status: Obligations to Persons and Other Living Things (Oxford: Clarendon Press 1997).Google Scholar

6 Creating the Kingdom of Ends (New York: Cambridge University Press 1996), 351. It should be noted that although she presents this as a Kantian view, Korsgaard allows that it is not a view Kant explicitly held; she points out that in his Anthropology from a Pragmatic Point of View, Kant claims that, in principle, scientists could determine whether an individual possesses the capacities sufficient for having moral standing.

7 Ibid., 356-7.

8 Some of the most prominent proponents of these prominent criteria of moral standing are, in order: Kant, Immanuel Groundwork of'the Metaphysics of Mords, 429;Google Scholar Rawls, John A Theory of Justice (Cambridge: Harvard University Press 1971), 505Google Scholar (it is worth noting, however, that Rawls uses this as a criterion of political, rather than moral, standing in Political Liberalism (New York: Columbia University Press 1996), xlv); Nozick, Robert Anarchy, State, and Utopia (New York: Basic Books 1974), 48–51;Google Scholar Scanion, T.M. What We Owe to Each Other (Cambridge: Harvard University Press 2001), 185;Google Scholar Regan, Tom The Case for Animal Rights (Berkeley: University of California Press 1983), 243;Google Scholar Bentham, Jeremy Introduction to the Prindples of Marals and Legislation, eh. 18, sect. 1.Google Scholar In addition, some authors combine several of these criteria. Dworkin, for instance, combines the criteria of Nozick, Rawls and Scanion when he says that we deserve moral Standing in virtue of being ‘human beings with the capacity to make plans and give justice’ (Taking Rights Seriously [Cambridge: Harvard University Press 1977], 184).Google Scholar

9 For influential Statements of this objection to egalitarianism, see Lucas, J.R. ‘Against Equality,’ Philosophy 40 (1965), 297CrossRefGoogle Scholar and Williams, Bernard ‘The Idea of Equality,’ in Problems of the Seif (Cambridge: Cambridge University Press 1973), 230.CrossRefGoogle Scholar

10 For a more comprehensive discussion of justifications of egalitarianism, see Pojman's, Louis helpful ‘Are Human Rights Based on Equal Human Worth?’ Philosophy and Phenomenological Research 52 (1992) 605–22.CrossRefGoogle Scholar

11 Rawls, A Theory of Justice, 508.Google Scholar Charles Larmore echoes this response when he writes of his proposed criterion of moral standing — the capacity to work out a coherent view of the world — that, ‘Of course, some people have this capacity to a greater degree than others do, but respect is something that others as persons are due just by virtue of having that capacity, so it should be given equally to all’ (Patterns of Moral Complexity [Cambridge: Cambridge University Press 1987], 64). Williams's response to the problem posed by the descriptive differences between normal adult humans — that we should remind ourselves that ‘all men are men’ — is similar in spirit. See ‘The idea of equality’, 230..

12 Although the meaning of species terms is a matter of dispute within the philosophy of biology, the vagueness of ‘human’ is suggested by the fact that, on nearly all accounts, the species homo sapiens emerged gradually over a long interval rather than at a precise point in time. See, for instance, Mayr's, Ernst discussion of transitional ‘semi-species’ in his ‘What Is a Species, and What Is Not?’ Philosophy of Science 63 (1996) 273–4.CrossRefGoogle Scholar

13 While it is undeniable that the two individuals will both be borderline cases of 'rational’, those who hold some non-truth-value-gap theory of vagueness will resist the claim that they are therefore identical with respect to the proposed criterion for moral standing. I will discuss one such theory—epistemicism—later in this section. I will not explicitly discuss the degree theorist's proposal that, for one of these individuals, it is ‘more true’ that it is rational. But the most straightforward way of accommodating this approach to vagueness would be to adopt the approach to moral standing I recommend in section V.

14 Timothy Williamson shows how, given highly plausible assumptions, second-order vagueness leads to vagueness of all Orders in his ‘On the Structure of Higher-Order Vagueness’, Mind 108 (1999) 127-43. The argument from the existence of vagueness of all Orders to the conclusion that any human is some order of borderline rational goes as follows: construct a finite series of individuals who differ only minutely in their cognitive capacity that ranges from those that possess the capacity of a chicken to those that possess super-human capacities. It is clear that f ewer of these individuals will be definitely rational than are rational; fewer will be definitely definitely rational than are definitely rational; and so on. The existence of vagueness of all Orders insures that the ‘definitely’ Operator can be iterated indefinitely, and each iteration of ‘definitely’ reduces the number of individuals in our finite series who fall under the description until none do. So those with super-human capacities will be borderline cases of some order of definite rationality. So all humans will be borderline cases of some (lower) order of definite rationality. See Williamson, Vagueness, 160-1.

15 This liberal’ stance should not be confused with the pragmatic policy that is sometimes called ‘playing it safe.’ According to this policy, if we are unsure whether an individual possesses moral Standing, we should treat the individual as if it does. This policy is not without its moral costs: for instance, if an individual about whom we are unsure does in fact lack moral Standing, the policy will sometimes recommend restricting those who do have moral Standing for its sake. In such cases, the restricted individual has a valid moral complaint. But in the current context this is really beside the point, for the pragmatic policy of ‘playing it safe’ is not an account of what moral Standing individuals actually possess, but rather, a recommendation of how to cope with our uncertainty regarding that issue.

16 This way of putting the point was inspired by the discussion of continua in Temkin's, Larry ‘A Continuum Argument for Intransitivity’, Philosophy and Public Affairs 25 (1996) 175–210.CrossRefGoogle Scholar

17 See, for instance, Williamson, Timothy Vagueness (New York: Routledge 1994),Google Scholar chs. 7 and 8.

18 Williamson, Vagueness, 231Google Scholar

19 Torin Alter and Stuart Rachels make a similar point concerning epistemicism and theories of personal identity in their ‘Epistemicism and the Combined Spectrum Argument’, Ratio 17 (2004) 241-55.

20 Sumner, L.W. Abortion and Moral Theory (Princeton: Princeton University Press 1981), 150.CrossRefGoogle Scholar The emphasis is mine. Other authors who are tempted by the notion of indeterminate Status include Roger Wertheimer (see his ‘Understanding the Abortion Argument’, Philosophy and Public Affairs 1 [1971], 88) and Jeff McMahon (see his The Ethics of Killing: Problems at the Murgins of Life [New York: Oxford University Press 2002], 265).

21 Anarchy State and Utopia, 39

22 Other gestures towards such a two-tiered view are made in Rawls, John A Theory of Justice, 512,Google Scholar and Dworkin, Ronald Life's Dominion (New York: Alfred A. Knopf 1993), 85.Google Scholar

23 Do this theory's commitments regarding what we owe individuals just above and below the threshold for utilitarian respect also violate the ideal of proportionality? Perhaps not, if my characterization of the ideal is exhaustive. For it may be that the interests of the individuals just above the threshold will be of the very weakest sort, and hence that this theory can claim that they will generate only the weakest of moral reasons. If so, the treatment owed to those individuals just above and below the threshold may be similar. But matters are less clear if the ideal of proportionality requires more than just avoiding drastically different treatment of similar individuals. If, for instance, the ideal requires calibrating differences in treatment as finely as possible to the morally relevant descriptive differences, or if it applies not only to individuals but also to individuals’ interests, then it may be that Standard versions of utilitarianism contravene the ideal. I leave these issues to future work.

24 Or, if there is only one kind of moral Standing, then the theory musthold that, among those who possess less moral Standing than people do, there are some that deserve a level of concern or respect that is very similar that deserved by people, and others who deserve a level of concern and respect that is very similar to that deserved by those who have no moral Standing at all.

25 Indeed, there is a case to be made that our discomfort with arbitrariness in moral matters arises from the fact that arbitrary moral distinctions typically involve violating the ideal of proportionality. If this is right, then the line this theory draws between those who deserve an infinitesimally small amount of respect or concern and those who deserve none is an instance of morally innocuous arbitrariness, as making this particular distinction in this way is consistent with the ideal of proportionality.

26 This is, for instance, the way Francis Kamm understands the proposal that humans have a standing that makes them absolutely ‘inviolable.’ (She, however, rejects such a view as according individuals an excessive degree of protection.) See her ‘Non-Consequentialism, the Person as an End-in-Itself, and the Significance of Status’, Philosophy and Public Affairs 21 (1992), 383-4.

27 I make some initial suggestions regarding how this might be done in my ‘Species Inegalitarianism as a Matter of Principle’, Journal of Applied Philosophy, forthcoming.