According to David Miller, there are two ways to think about justice. Platonic approaches to justice are based on universal moral truths – values that are independent of both common sense morality and the context to which they are applied (3).Footnote ¹ These Platonic truths can be discovered independently of empirical information concerning societies and institutions, or the abilities and vulnerabilities of actual human beings. Justice for earthlings, by contrast, allows that principles of justice might vary with the context to which they are applied. According to this approach, theories of justice should be sensitive to facts about human nature and societies and to the (considered) judgements of actual people.

Miller defends justice for earthlings. He argues that Platonic political philosophy, most notably exemplified in the work of G. A. Cohen, not only fails to understand how justice is inherently rooted in actual social practices and institutions, but also ‘places justice so far out of the reach of human beings that nothing we can practically achieve will bring us significantly closer to the cherished goal’ (230). If we follow the Platonic approach to political philosophy, then all there is left for us is to lament over the enormous gap between Platonic values and the actual conditions of human life. In the approach Miller advocates, the actual conditions of our life are allowed to shape our thinking about justice, so that we can arrive at a theory of justice that is not only action-guiding, but which also ‘takes the ordinary use of language as a touchstone’ (57).

One of the book's many strengths is that Miller not only argues for this methodological position (Chapter 1, 2 and 10), but that he also aims to show how this methodology makes a substantive normative difference. He does so by applying his approach to questions about multiculturalism (Chapter 3), equality of opportunity (Chapters 4 and 5), global justice (Chapters 6 and 7) and responsibility (Chapters 8 and 9). In the book's best moments, Miller convincingly integrates normative and empirical analysis in order to formulate highly practical policy proposals, for instance by discussing the impact of specific situations for our ability for altruistic behaviour, or the importance of the family for the opportunities of children.

However, the book also illustrates that theorizing for earthlings comes at a cost. By rejecting (most) universal moral theorizing, Miller runs the risk of embracing a rather ad hoc approach to justice. Most troubling, Miller does not always provide sufficient moral arguments in favour of his substantive normative position. One is therefore left wondering whether there is no middle ground between Platonic justice and justice for earthlings. Yet these worries should not distract us from the book's important main message, i.e. that justice has an essential role to play in human practices and institutions and that theorizing about justice is not just of theoretical interest.

The book contains ten previously published papers, which are preceded by a new introduction. In this short review, I cannot do justice to all the arguments and insights the book has to offer. I will therefore focus on some salient issues.

One of the substantive normative debates Miller engages in, concerns the relation between equality of opportunity and culture (Chapter 4) and equality of opportunity and the family (Chapter 5). Miller claims that a plausible conception of equality of opportunity should take into account the cultural costs of specific choices, i.e. opportunity costs caused by membership in a cultural group. According to Miller, ‘real’ equality of opportunity has to go beyond formal and legal rights to equal opportunities. Instead, equality of opportunity means being able to do something without bearing excessive costs (113). More concretely, Miller argues that if a Sikh wishes to send his son to a school where the wearing of turbans is forbidden, the opportunity for the child to attend school is blocked because the cultural costs of not wearing a turban are unreasonably great (103). Without trying to provide an comprehensive account of ‘unreasonable costs’, Miller opts for a democratic solution and claims that in order to determine whether or not specific cultural requirements or commitments actually entail unreasonable costs, we have to engage, on a case by case basis, in a political dialogue with different groups in order to evaluate the significance of these cultural commitments for individual's identity and the extent to which these requirements and commitments could be changed (114).

Whereas Miller extends equality of opportunity to incorporate cultural costs, he is more hesitant to include costs that are related to the family. For example, in order to evaluate whether gender norms that are transmitted through the family generate injustices, one has to show ‘that daughters cannot depart from the norm without incurring unreasonable costs’ (139). According to Miller, ‘[f]or some women this will be true but, in liberal societies at least, for most it will not’ (139). Thus, according to Miller, (most) women have the opportunity to do otherwise without having to bear unreasonable costs.

In arguing for this conclusion, Miller criticizes a luck-egalitarian principle according to which all inequalities that result from brute luck are unjust. Miller rejects interpretations of luck-egalitarianism that define luck too broadly on grounds that they collapse into some form of equality of outcome. Miller proposes to draw a line between a ‘person’ and her ‘circumstances’. According to Miller, we should only compensate for inequality generated by (social) circumstances but not for inequality generated by personality, which includes tastes, character and capacities (136). Inheriting wealth from your family generates unfairness because it changes your circumstances to such an extent that it undermines equality of opportunity (137). Yet according to Miller, there is no unfairness if one reads bedtime stories to one's child, when others’ children are not read to, even if this has impact on the child's capacities and character. The reason for this is that, according to Miller, reading bedtime stories to a child may affect the personality of the child but not the social circumstances (139). Analogously, the transmission of gender norms may affect the personality of a children but it does not unreasonable diminish their opportunities.

I am not sure how exactly Miller's argument against luck-egalitarianism is supposed to work. Even though Miller might be right that in practice a luck egalitarian principle collapses into some form of equality of outcome, I do not see why this is a reductio ad absurdum of the luck-egalitarian principle. In addition, it is not clear why the distinction between ‘personality’ and ‘circumstances’ is morally relevant. Why should we compensate for inequality caused by circumstances and not for personality, including the influence of family on tastes, character and capacities? Miller does not provide an argument but simply claims that the family's influence on the personality of a child, for instance through encouraging certain career choices, ‘does not diminish their opportunities to do otherwise’ (139). This claim at least presupposes a controversial empirical premise, namely that transmission of advantage through the family is not that significant. In addition, the distinction between personality and circumstances is itself not unproblematic. Surely, one's tastes, character and capacities do not exist independently of the circumstances in which one is raised. Miller explicitly acknowledges this when he argues against luck egalitarianism, but it is conspicuously absent in his own considerations about the influence of the family on opportunities (118–119).

Furthermore, Miller's hesitancy to extend justice into the family sits somewhat uneasily with the rather extensive accommodation of cultural requirements and commitments. In a footnote (121), Miller acknowledges that whereas in the chapter on multiculturalism he assumed that opportunity costs should be roughly the same for each agent in order for equality of opportunity to be achieved (strong equality of opportunity), he actually changed his view and now thinks that justice is satisfied if agents have identical opportunity sets even though opportunity costs might be different for each agent (weak equality of opportunity). It is, however, a real omission that Miller does not elaborate on the tension between these two interpretations of equality of opportunity, especially since in both cases it remains unclear why Miller favours one interpretation over the other.

A second issue I want to discuss is Miller's analysis of the site of justice and the relation between social and global justice. Unsurprisingly in light of his earlier work (Miller Reference Miller2007), Miller argues that given the world as it is, nation states are still the privileged site of social or distributive justice. Miller discusses three well-known arguments for limiting the site of justice to the nation state: the claim that justice applies only to cooperative practices, the claim that the question of justice arises only in contexts of political coercion, and the claim that justice requires a common identity (151–161). According to Miller, taken on their own, none of these arguments is adequate, but taken together they constitute a strong argument in favour of limiting the site of justice to nation states (151).

Miller claims that this limitation of the site of justice to nation-states only applies to social or distributive justice (144–145). According to Miller, minimal standards of global justice, those related to securing basic human rights, do apply universally, independently of boundaries and group membership (145, 173). Thus, distributive justice only concerns the distribution of advantage that goes beyond the distribution of advantage that is needed to guarantee basic human rights.

Miller defends a needs-based approach to human rights. To determine basic human rights ‘we begin with the idea that a decent human life contains certain essential components that are reiterated across all societies, and on that basis identify generic human needs whose precise form will nonetheless vary somewhat from one society to the next’ (173). Corresponding to these generic human needs, we have a set of human rights, some of which are primarily rights to non-interference (such as rights to freedom of movement and expression) but others of which are rights to positive provision (to the means of subsistence, basic healthcare and so forth).

Basic human rights are thus exempt from Miller's contextualism – the idea that principles of justice are different relative to the context to which they are applied. But given the enormous distributive implications of even a minimal set of basic human rights, Miller's dichotomies between universalism and contextualism and between globalism and nationalism are drawn into question.

There is however an important normative implication of Miller's explicit commitment to contextualism and nationalism. He rejects the idea that guaranteeing even basic human rights necessarily has priority over social or distributive justice within nation states. In consequence, Miller claims that there will always be what he calls ‘justice gaps’, meaning that ‘people in poor countries may have claims of justice against the citizens of rich countries – claims for resources to be sent in their direction or for protection against various forms of local oppression – which those citizens can justifiably refuse to meet in the name of social justice’ (179). One would expect an argument for such a controversial claim. But Miller avoids this: ‘I have not (…) tried to provide an independent argument for giving priority to social justice in cases such as those described. Instead I have appealed to what I hope may be shared understandings on the part of readers of what is owed to fellow citizens’ (179).

It is doubtful, however, that readers, especially those familiar with the global justice debate, will share this nationalist bias. More importantly, even if there is such a shared understanding, it is not clear that we should take existing biases towards fellow nationals as input into theorizing about justice, instead of criticizing these biases. My point here is not necessarily that we shouldn’t, but rather that such a claim requires argument and justification. This issue is all the more pressing given the fact that in other places Miller criticizes existing judgements about justice. Not only does he explicitly claim that his contextualism should not be confused with ‘conventionalism’ (49), he also criticizes people's unjustifiable resistance against inheritance taxation (181).

Miller is indeed not a conventionalist. Instead, he claims throughout the book that he is using the method of Reflective Equilibrium, according to which principles of justice are justified when there is coherence between principles, judgements and (in some versions) moral and empirical background theories. This implies that we should not assign special authority to people's (considered) judgements, but that revision of those judgements in light of principles or background theories may sometimes be appropriate. Miller argues for revision in the case of inheritance taxation, but not in the case of our bias towards fellow nationals. However, even if one accepts this methodology, one should try to convince the reader why in one case we have to accept the judgements of actual people, and why in another case these judgements should be revised. My worry is that, by failing to provide sufficient argument for his favoured position, Miller is cherry-picking people's judgements about justice.

Let me finish this review with some general remarks on Miller's methodology. Miller seems to assume that one either has to be searching for Platonic values or one has to embrace his contextualist approach to justice. Both extremes seem to have problems of their own. Not many people are willing to bite the Platonic bullet and accept Cohen's claim that ‘the question for political philosophy is not what we should do but what we should think, even when what we should think makes no practical difference’ (Cohen Reference Cohen2003: 243). However, for many it is equally problematic to reject universal and abstract theorizing in favour of immediate practical impact.

Miller might be right that the question of what justice requires depends on specific contexts, but this does not undermine universalism as such. One can be sensitive to contexts of justice when formulating applied principles of justice that should regulate actual institutional design and resource allocation, while being a universalist at the level of the formulation of fundamental principles of justice, those principles that determine under which conditions applied principles of justice can be morally justified. For example, Kantian theories of justice propose minimal and fundamental principles of justice (such as a rejection of principles based on deceit, injury and unjustifiable coercion), which form the background against which citizens themselves can decide on more applied principles. Rainer Forst, for instance, agrees with Miller that (applied) principles of justice should differ according to their context of application. Individuals should themselves be able to decide on appropriate distributive principles through actual deliberation. Yet Forst stresses that applied principles of justice can only be morally justified if they are reciprocally and generally acceptable (Forst Reference Forst2011: 6). This means that one cannot deny demands from others which one raises for oneself, and that reasons must be shareable by all those relevantly affected. Although this fundamental principle of mutual justifiability is itself universally valid it obviously does not require uniform action in all circumstances. Instead, it proposes the conditions under which an answer as to the question of what justice requires can be justified (see also O’Neill Reference O’Neill2000).

It seems that the most plausible theory of justice combines the universalism of fundamental principles of justice with the contextualism of applied principles. I think it is therefore not surprising that Miller himself allows universalism to come in through the back door, by claiming that there is a set of morally justifiable universal moral rights. In fact, at another point, Miller explicitly admits that ‘perhaps the most defensible theory will turn out to be located somewhere in the middle’ (45) and he hints at the possible existence of a ‘meta-principle, a guide for arriving at valid political principles for each planet [circumstance]’ (p. 39). It is therefore unfortunate that Miller forces us into a false dichotomy between Platonic justice and justice for earthlings, instead of trying to elaborate the structure of a more moderate and hence more defensible approach, which is located somewhere in the middle.

Despite these methodological shortcomings, Justice for Earthlings offers an engaging analysis of a wide range of pressing normative issues. The book is first and foremost a strong plea for theories of justice that are not just theoretically sophisticated but practically relevant. Justice has an important place in the human form of life, and is of more than just theoretical interest. This message can only be applauded.