Rawls ignited a debate in political theory when he introduced a division between the ideal and nonideal parts of a theory of justice. In the ideal part of the theory, one presents a positive conception of justice in a setting that assumes perfect compliance with the rules of justice. In the nonideal part, one addresses the question of what happens under departures from compliance. Critics of Rawls have attacked his focus on ideal theory as a form of utopianism, and have argued that political theory should be focused instead on providing solutions to the manifest injustices of the real world. In this essay, I offer a defense of the ideal/nonideal theory distinction according to which it amounts to nothing more than a division of labor, and explore some scientific analogies. Rawls’s own focus on the ideal part of the theory, I argue, stems from a felt need to clarify the foundations of justice, rather than a utopian neglect of real world problems.

The science underlying global warming, climate change, and the connections between these phenomena are reviewed. Projected future climate changes under various plausible scenarios of future human behavior are explored, as are the potential impacts of projected climate changes on society, ecosystems, and our environment. The economic, security, and ethical considerations relevant to determining the threat posed by climate change are subsequently assessed. The article then discusses the various means available for climate change mitigation, focusing on the relative strengths and weaknesses of various societal alternatives including ‘geoengineering’ and transitioning to less carbon intensive energy sources. The article concludes with the author's views as to what steps might most profitably be taken to avert dangerous anthropogenic interference with Earth's climate, and the ramifications if such steps are not taken.

In a providential account of the changing relation between political economy and economics, the late nineteenth-century development of economics is identified with the rational choice model; and the revival of political economy in the late twentieth century comes with the export of this model to politics and the other social sciences. An alternative prudential account locates the revival of political economy with a significant qualification to the rational choice model. This qualification restores an eighteenth- and nineteenth-century view of rule-following to human agency. This essay sets out these accounts and draws the conclusion that the choice of one over the other matters, not least for the practice of contemporary politics.

Political philosophy appears to have recovered from its alleged death in the middle of the last century, but now faces the realist charge that in the work of John Rawls and those influenced by him it fails to be political in the right way; it is merely “applied moral philosophy.” I dismiss the hyper-realist position of authors such as Raymond Geuss for taking an implausibly narrow view of politics. There is more merit in Bernard Williams’s claim that legitimacy, not justice, is the central problem of political philosophy. Yet we cannot understand the significance of legitimation without referring to the moral values that are realized when it succeeds. Thus, Williams fails to show that political normativity can be detached entirely from ethics. Moreover the legitimacy requirements of a liberal state, according to Williams, are substantively close to the requirements of justice according to Rawls. In light of the latter’s turn to “political liberalism,” they appear also to hold convergent views about the status of the theories they are advancing. I conclude by suggesting that the “applied moral philosophy” charge would apply only to philosophers who believe that general moral principles, like utility or rights, can do all the work of political evaluation. Politics does indeed have special features that impose distinctive justificatory requirements on its procedures and the outcomes they produce.

Utilitarians and their critics commonly assume that maximizing utilitarianism necessarily aggregates over cardinal comparable personal utility rankings that are homogeneous in quality independently of their sources or objects, whether utility is conceived in terms of pleasure or preference satisfaction. Although familiar versions of utilitarianism, crude or sophisticated, do make such rich homogeneous utility information part of the very meaning of the doctrine, utilitarian philosophy loses credibility as a result. A more credible version of maximizing utilitarianism along John Stuart Mill's lines relies instead on plural kinds of ordinal non-comparable personal utilities that are heterogeneous in quality. One kind of utility is qualitatively superior to another if and only if the higher kind is more valuable than the lower kind irrespective of quantity. Given that the kind of utility associated with the moral sentiment of justice is qualitatively superior to any competing kinds, Mill's pluralistic ordinal utilitarianism gives absolute priority to a social code of equal rights and duties over competing considerations. Some key practical implications of this extraordinary utilitarianism are discussed with reference to various examples of the sort discussed in the literature.

It is common to regard love, friendship, and other associational ties to others as an important part of a happy or flourishing life. This would be easy enough to understand if we focused on friendships based on pleasure, or associations, such as business partnerships, predicated on mutual advantage. For then we could understand in a straightforward way how these interpersonal relationships would be valuable for someone involved in such relationships just insofar as they caused her pleasure or causally promoted her own independent interests. But many who regard love, friendship, and other associational ties as an important part of a happy or flourishing life suppose that in many sorts of associations—especially intimate associations—the proper attitude among associates is concern for the other for the other's own sake, not just for the pleasure or benefits one can extract from one's associates. It is fairly clear how having friends of this sort is beneficial. What is less clear is how being a friend of this sort might contribute to one's own happiness or well-being. Even if we can explain this, it looks as if the contribution that friendship makes to one's happiness could not be the reason one has to care for friends, for that would seem to make one's concern for others instrumental, not a concern for the other for her own sake.

Social and behavioral scientists — that is, students of human nature — nowadays hardly ever use the term ‘human nature’. This reticence reflects both a becoming modesty about the aims of their disciplines and a healthy skepticism about whether there is any one thing really worthy of the label ‘human nature’.

For some feature of humankind to be identified as accounting for our ‘nature’, it would have to reflect some property both distinctive of our species and systematically influential enough to explain some very important aspect of our behavior. Compare: molecular structure gives the essence or the nature of water just because it explains most of its salient properties. Few students of the human sciences currently hold that there is just one or a small number of such features that can explain our actions and/or our institutions. And even among those who do, there is reluctance to label their theories as claims about ‘human nature’.

Among anthropologists and sociologists, the label seems too universal and indiscriminant to be useful. The idea that there is a single underlying character that might explain similarities threatens the differences among people and cultures that these social scientists seek to uncover. Even economists, who have explicitly attempted to parlay rational choice theory into an account of all human behavior, do not claim that the maximization of transitive preferences is ‘human nature’.

I think part of the reason that social scientists are reluctant to use ‘human nature’ is that the term has traditionally labeled a theory with normative implications as well as descriptive ones.

The definition above nicely encapsulates two of the intertwined meanings of ‘privacy’. In the first sense—physical seclusion—the level of privacy in modern developed societies is extraordinarily high by historical standards. We take it for granted that a bed in a hotel will be occupied by either one person or a couple—not by several strangers. At home, few of us expect to share either bed or bedroom with our children. In these and a variety of other ways, increased physical privacy has come as a byproduct of increased wealth.

While citizens of developed countries enjoy lives of unmatched affluence, over a billion people struggle to subsist on incomes of less than $1/day. Can't we conclude that their poverty constitutes a glaring injustice? The answer almost certainly is yes—but not because some countries are rich, nor because of inadequate levels of redistribution. Liberal political theory traditionally maintains that persons are rights-holders, and the primary duty owed them is noninterference. Corrupt and tyrannical governments flagrantly violate the liberty rights of their captive populations. External governments conspicuously fail to respect noninterference, however, when they erect barriers to trade between foreign nationals and their own citizens, subsidize domestic industries, prevent innocent movement across borders by would-be workers, and when they tender assistance to abusive states (such as foreign aid that lines the pockets of kleptocrats and enhances their power). The theory advanced here is similar to that of Rawls in rejecting an international difference principle, but unlike Rawls it advances an account of international justice as continuous with domestic principles of justice.

Let me begin with what should be a reassuring thought, and one that may serve as a corrective to presumptions that sometimes characterize political philosophy. The possibility, which Aquinas and Madison are both concerned with, of wise and virtuous political deliberation resulting in beneficial and stable civil order, no more depends upon possession of aphilosophical theory of the state and of the virtues proper to it, than does the possibility of making good paintings depend upon possession of an aesthetic theory of the nature and value of art.

(1) In his recent paper, “Justice as Fairness: Political not Metaphysical,” John Rawls makes use of a footnote to disown what to many readers must have seemed one of the most striking and original underlying ideas of his theory of justice, that it “is a part, perhaps the most significant part, of the theory of rational choice.” That Rawls should issue this disclaimer indicates, at least in my view, that he has a much clearer understanding of his theory, and its relationship to rational choice than he did at the time that he wrote A Theory of Justice. As I note in Morals by Agreement (pp.4–5), Rawls does not show that principles of justice are principles of rational choice. Hence, in appropriating the idea, I can claim diat I am undertaking a pioneering enterprise. No doubt Thomas Hobbes would have undertaken it had the resources of the theory of rational choice been at his disposal, but I do not intend to pursue counterfactuals in a search for historical antecedents. Moral theory as rational choice theory is, I claim, a new venture.

A broad range of intellectual perspectives may be brought to bear on any important social institution. To this general rule, the institution of private property is no exception. The desirability of private property has been endlessly debated across the disciplines: philosophical, historical, economic, and legal. Yet there is very little consensus over its proper social role and limitations. Is it possible to find a unique solution to questions of property and private ownership, good for all resources and for all times? The famous defense of private property that is found in chapter 5 of John Locke's Second Treatise of Government answers this question in the affirmative, for Locke writes as though all property was given to mankind in common, and then seeks to find the quickest and most expeditious way to convert all common property into private property. His implicit, but undefended, assumption is that common forms of property are both undesirable and unstable, while private forms of ownership are always just the opposite. Yet his preferred method for moving from a commons to a regime of private property—the unilateral decision to appropriate by each actor—is one that has been frequently condemned as a sop to unbridled egotism, even though it is subject to two constraints: the first against waste, and the second requiring the appropria-tor to leave “enough, and as good” for others.

The strengths and weaknesses of federalism have been debated for centuries. But one major possible advantage of building decentralization and limited government into a constitution has been largely ignored in the debate so far: its potential for reducing the costs of widespread political ignorance. The argument of this paper is simple, but has potentially important implications: Constitutional federalism enables citizens to “vote with their feet,” and foot voters have much stronger incentives to make well-informed decisions than more conventional ballot box voters. The informational advantage of foot voting over ballot box voting suggests that decentralized federalism can increase citizen welfare and democratic accountability relative to policymaking in a centralized unitary state.

Ballot box voters have strong incentives to be “rationally ignorant” about the candidates and policies they vote on because the chance that any one vote will have a decisive impact on an electoral outcome is vanishingly small. For the same reason, they also have little or no incentive to make good use of the information they do possess. By contrast, “foot voters” choosing a jurisdiction in which to reside have much stronger incentives to acquire information and use it rationally; the decisions they make are individually decisive.

A question that has recently attracted considerable attention is this:

What is the nature and significance of the normative relationship a person bears to herself (where the self is understood to include the whole embodied person)?

On one view, it is held that persons are self-owners: as Locke put it in one of the more famous passages in the Second Treatise:

[E]very man has a property in his own person: this no body has any right to but himself. The labour of his body, and the work of his hands, we may say, are properly his.

A theory of basic moral rights ought to aim at telling us who the beings are that have rights and of what those rights consist. It may, however, seek to achieve that goal via an indirect route. In this paper I shall attempt a strategy of indirection. The first stage of the argument is a consideration of why moral theory can allow any place at all to rights. Acknowledging rights can be inconvenient. An otherwise desirable outcome is blocked if the only ways in which it can be attained involve the violation of rights. Why not jettison rights and thereby render these outcomes achievable? The answer that will be suggested trades on it being a deep fact about human beings that they can and do order their lives by reference to long-term commitments and aspirations. In my terminology, they are project pursuers. If people were rational animals all of whose interests were flickering and evanescent, an ethic entirely resting on maximization of impersonal value would be appropriate. But because projects entail commitments to values not subject to trade-offs, the introduction of rights is plausible.

That is the first major stage of the argument. The second builds on it and tries to show that the recognition of rights or their equivalent is morally required, that only an ethic in which basic rights are acknowledged can be properly responsive to persons' status as project pursuers. More particularly, is suggested that rights take the form of constraints imposing minimal forbearance on others such that one has reasonable expectations of being able to pursue one's projects amidst a world of other project pursuers.

Although dignity figures prominently in modern ethical discourse, and in the writings of moral and political philosophers writing today, we still lack a clear account of how the concept of dignity might be implicated in various forms of moral reasoning. This essay tries to make progress on two fronts. First, it attempts to clarify the possible roles the concept of dignity might play in moral discourse, with particular reference to Hart's distinction between positive and critical morality. Second, it offers a new typology of dignity concepts and mobilizes it to, on the one hand, criticize some familiar construals of “human dignity” and, on the other, to advertise the possible virtues of an unfamiliar way of thinking about dignity as a moral concept.

The debate over whether philosophy makes progress has focused on its failure to answer a core set of “big” questions. I argue that there are other kinds of philosophical progress which are equally important yet underappreciated: the creative development of new “philosophical devices” which increase our ability to think about the world, and the broadening of philosophical topics to ever greater adequacy to what matters. The conception of philosophy as defined by a narrow “core” set of questions is responsible for skepticism about progress, as well as for philosophy’s “marketing problem” — its failure to reach the general public. I argue for abandoning the distinction between “core” and “marginal” questions. The greater openness of philosophy to methodological diversity and diversity in topics, especially applied topics, will make a distinct kind of progress: in the breadth and completeness of the questions asked, phenomena investigated, and theories generated. Such openness may also make philosophy more hospitable to more diverse practitioners. This would also be conducive to progress, in the sense of reaching true answers to philosophical questions: greater diversity of philosophical practitioners has epistemic benefits, such as increasing objectivity.

In this essay, I survey egalitarian and utilitarian approaches to the distribution of scarce life-saving medical resources. In my view, the major criterion for the distribution of scarce life-saving medical resources (hereinafter sometimes the “distribution of life”) should be life expectancy: we should distribute life so as to maximize life-years. In Section II, I discuss the life-year maximization approach and situate it within utilitarian theory.

I present what I take to be the “classical” approach to property rights, in which property is basically a unitary concept: owners are the ones with the right to do, and prohibit others from doing, whatever there is to do with the thing owned, within the limits imposed by the rights of others to their things. I expound and defend the idea of “first acquisition” in more or less Lockean mode. I also point to the many difficulties of application of the general idea, leading to the need to negotiate at many points. For example, the vagueness of land ownership as we consider what goes on in the earth below or the sky above; to consideration of not just possible physical damages to others by virtue of ownership, but also aesthetic ones; and to the increasingly important area of intellectual property. I argue that the original idea continues to hold, though it underdetermines any number of specific issues.