Immigration is a divisive policy issue in modern liberal democracies. A common worry is that immigration poses a threat to social cohesion, and so to the social unity that underpins cooperation, stable democratic institutions, and a robust welfare state. At the heart of this worry is the suggestion that social cohesion requires a shared identity at the societal level. In The Politics of Social Cohesion, Nils Holtug gives a careful assessment of the impact of immigration on social cohesion and egalitarian redistribution. First, he critically scrutinizes an influential argument, according to which immigration leads to ethnic diversity, which again tends to undermine trust and solidarity and so the social basis for redistribution. According to this argument, immigration should be severely restricted. And second, he considers the suggestion that, in response to worries about immigration, states should promote a shared identity to foster social cohesion in the citizenry. Holtug argues that the effects of immigration on social cohesion do not need to compromise social justice, and that core principles of liberty and equality not only form the normative basis for just policies of immigration and integration but, as a matter of empirical fact, are also the values that, if shared, are most likely to produce the social cohesion among community members that provides the social basis for implementing justice.

National identity plays an increasingly important role in Western, liberal democracies. Thus, national identities are experienced as threatened by immigration and diversity and restrictions on immigration and nation-building policies are being implemented in response. Specifically, it has been suggested that diversity drives down social cohesion and thus the ties that bind people together in stable, democratic welfare states. This book addresses challenges to stable liberal democratic institutions and to social cohesion resulting from immigration and diversity. Thus, immigration has been considered an important factor in political polarization and political responses and movements. National identity plays a significant role both as something that, according to some, is threatened by diversity and as something to which populist politicians positively appeal in their justification of restrictive immigration policies and efforts towards nation-building. In some cases, political leaders have framed minorities as a threat to the nation state warranting a departure from liberal democratic institutions. This book considers the role of national identity in contemporary societies and in particular its significance for social cohesion. What role does national identity play for political polarization? Do national identities mediate/moderate the impact of diversity on social cohesion, including trust and solidarity? Has identity politics contributed to a politics of resentment and can more inclusive national identities serve to diminish polarization? In the book, these and other questions about the relation between national identity, belonging and social cohesion are considered by a number of the most prominent scholars in the field.

In our lives, we aim to achieve welfare for ourselves, that is, to live good lives. But we also have another, more impartial perspective, where we aim to balance our concern for our own welfare against a concern for the welfare of others. This is a perspective of justice. Nils Holtug examines these two perspectives and the relations between them.
The first part of the book is concerned with prudence; more precisely, with what the necessary and sufficient conditions are for having a self-interest in a particular benefit. It includes discussions of the extent to which self-interest depends on preferences, personal identity, and what matters in survival. It also considers the issue of whether it can benefit (or harm) a person to come into existence and what the implications are for our theory of self-interest. A 'prudential view' is defended, according to which a person has a present self-interest in a future benefit if and only if she stands in a relation of continuous physical realization of (appropriate) psychology to the beneficiary, where the strength of the self-interest depends both on the size of the benefit and on the strength of this relation.
The second part of the book concerns distributive justice and so how to distribute welfare or self-interest fulfilment over individuals. It includes discussions of welfarism, egalitarianism and prioritarianism, population ethics, the importance of personal identity and what matters for distributive justice, and the importance of all these issues for various topics in applied ethics, including the badness of death. Here, a version of prioritarianism is defended, according to which, roughly, the moral value of a benefit to an individual at a time depends on both the size of the benefit and on the individual's self-interest, at that time, in the other benefits that accrue to her at this and other times.

Egalitarianism, the view that equality matters, attracts a great deal of attention amongst contemporary political theorists. And yet it has turned out to be surprisingly difficult to provide a fully satisfactory egalitarian theory. The cutting-edge articles in Egalitarianism move the debate forward. They are written by some of the leading political philosophers in the field. Recent issues in the debate over equality are given careful consideration: the distinction between 'telic' and 'deontic' egalitarianism; prioritarianism and the so-called 'levelling down objection' to egalitarianism; whether egalitarian justice should have 'whole lives' or some subset thereof as its temporal focus; the implications of Scanlon's contractualist account of the value of choice for egalitarian justice; and the question of whether non-human animals fall within the scope of egalitarianism and if so, what the implications are. Numerous 'classic' issues receive a new treatment too: how egalitarianism can be justified and how, if at all, this value should be combined with other values such as desert, liberty and sufficiency; how to define the 'worst off' for the purposes of Rawls' difference principle; Elizabeth Anderson's feminist account of 'equality of relations'; how equality applies to risky choices and, in particular, whether it is justifiable to restrict the freedom of suppliers who wish to release goods that confer different levels of risk on consumers, depending on their ability to pay. Finally, the implications of egalitarianism and prioritarianism for health care are scrutinized. The contributors to the volume are: Richard Arneson, Linda Barclay, Thomas Christiano, Nils Holtug, Susan Hurley, Kasper Lippert-Rasmussen, Dennis McKerlie, Ingmar Persson, Bertil Tungodden, Peter Vallentyne, Andrew Williams, and Jonathan Wolff.