In the Preface to this enormous work, Derek Parfit makes a reference to Sidgwick's ‘great, drab book’ The Methods of Ethics (xxxiii). The juxtaposition of adjectives is amusing and oddly endearing; for Parfit, Sidgwick's drabness is not in any serious competition with his greatness. Parfit's two-volume book is not drab – though it can be exhausting – and, although it is probably too early to tell for sure, it also shows certain signs of greatness. Time and time again, one is impressed, even moved, by Parfit's enthralling and indefatigable resourcefulness and level of immersion in these issues, and by his dogged and transparently sincere commitment to discovering the truth about them. Despite its length, On What Matters demands careful study by everyone with a serious interest in philosophical ethics.

What justifies differences in the acceptance of paternalism towards competent minors and older people? I propose two arguments. The first argument draws on the widely accepted view that paternalism is easier to justify the more good it promotes for the paternalizee. It argues that paternalism targeting young people generally promotes more good for the people interfered with than similar paternalism targeting older people. While promoting people's interests or well-being is essential to the justification of paternalism, the first argument has certain unfair implications in that it disfavours paternalism towards the worse off. The second argument caters to such fairness concerns. It argues that priority or inequality aversion supports age-differentiated paternalism because young people, who act imprudently and thereby risk their interests or well-being, are worse off than older people who act in similar ways. I suggest that both arguments are pertinent in evaluating specific paternalistic acts and policies.

John Stuart Mill's connection with the Irish question spanned more than four decades and embraced a variety of elements. Of his writings on Ireland, the best known are his forty-three Morning Chronicle articles of 1846–47 composed in response to the Famine, the section of the Principles of Political Economy that treats the issue of cottier tenancy and the problem of Irish land, and, most conspicuous of all, his radical pamphlet England and Ireland, published in 1868. All of these writings take the land question as their paramount concern. The fairly absorbing interest in the subject disclosed by Mill during the second half of the 1840s arose from the fortuitous conjuncture of the disaster unfolding in Ireland and his engagement with the principles of political economy. Between 1848 and 1871 Mill's Principles went through seven editions (excluding the People's edition) and the substantive revisions he made in the section on Ireland from one edition to the next illumine both the essence and the accidentals of his bearing towards that country. Mill's cogent and controversial advocacy of fixity of tenure in England and Ireland constituted the heart of his answer to the Fenian challenge. The land question aside, Mill was drawn into the battle over the Irish university system in the 1860s largely through his friendship with John Elliot Cairnes, professor of jurisprudence and political economy at the Queen's College Galway. On this subject, however, Mill wrote almost nothing for publication. The longest single piece he ever drafted on Ireland was his first, an essay that predated the Morning Chronicle articles by two decades. In his own bibliography this essay is referred to as ‘An article on the Catholic Question which appeared in the Parliamentary Review for 1825’. Although the essay of 1825 could justly have borne the same title as the pamphlet of 1868, the particulars of course differ markedly. Ireland never ceased to pose a question during the course of the nineteenth century, but the dynamics shaping that question changed much between the mid-1820s and the late 1860s. Even so, the 1825 essay prefigures something of Mill's later involvement with the Irish question, and also invites examination as a quite remarkable piece of political journalism from the pen of a young man not yet twenty, who would subsequently establish himself as the most influential thinker of his generation.

John Stuart Mill's defense of freedom of discussion in On Liberty remains a major influence on philosophical and public debates about free speech. By highlighting underappreciated textual evidence and key distinctions, this introduction attempts to show how the contributions of the symposium authors – Melina Constantine Bell, Rafael Cejudo, Christopher Macleod, and Dale E. Miller – point toward a more complete account of Mill's views.

Almost everyone believes that freedom from deprivation should have significant weight in specifying what justice between generations requires. Some theorists hold that it should always trump other distributive concerns. Other theorists hold that it should have some but not lexical priority. I argue instead that freedom from deprivation should have lexical priority in some cases, yet weighted priority in others. More specifically, I defend semi-strong sufficientarianism. This view posits a deprivation threshold at which people are free from deprivation, and an affluence threshold at which people can live an affluent life, even though their lives may be even further improved beyond that point. I argue that freedom from deprivation in one generation lexically outweighs providing affluence in another generation; in all other cases, freedom from deprivation does not have lexical priority.

As opposed to overdemanding principles which ask individuals to sacrifice too much, there are overpermissive principles which ask individuals to sacrifice too little. Determining the extent to which one should sacrifice often comes with the need of understanding what is of moral significance. By analysing different readings of moral significance, and singling out one specific interpretation of moral significance which links moral significance to gaining or losing a considerable amount of welfare, I demonstrate that one of the well-known principles of Peter Singer, the Weaker Principle of Sacrifice, is overpermissive as it exempts deliberately cultivated morally significant lavish pursuits from the domain of sacrifice. Overpermissiveness not only renders moral principles unreasonably broad but also causes burdens to be distributed unjustifiably in a comparative sense, where some parties are assigned a moral obligation whereas others are not.

Was Green a utilitarian? At least two studies suggest that he was, at least in some sense. One claim is inspired by Macpherson's association of nineteenth-century liberalism with utilitarianism. Drawing on this argument, Greengarten and Hansen claim that Green's departure from utilitarianism is only partial. His commitment to capitalism indicates a subscription to utilitarianism since the latter is the justificatory force of capitalist institutions.

I give and evaluate Prichard's many (often obscure and idiosyncratic) arguments against ideal utilitarianism.

It is hard to do justice, in a short reply, to Eyal's excellent review. Accordingly, I will focus on what I take to be its central claim – namely that I fail to give proper consideration to the extent to which the forced extraction of (live) body parts undermines individuals' opportunities for self-respect. According to Eyal, ‘body exceptionalism’ (the view that body parts, unlike material resources, are not appropriate subject matter for duties of justice) can be defended on the following grounds: ‘People usually see trespass into a person and into objects they associate with a person – especially into a person's body – as utterly disrespectful towards that person and her autonomy’ (pp. 236–7). And later: ‘Whether or not organ confiscation is truly disrespectful . . . its widespread and intractable perception as a humiliating violation counts heavily against it, because it can thwart opportunities for self-respect’ (p. 238).

The article considers a hierarchical theory that combines concern for two values: individual well-being – as a fundamental, first-order value – and (distributive) fairness – as a high-order value whose exclusive function is to complete the value of individual well-being by resolving internal clashes within it that occur in interpersonal conflicts. The argument for this unique conception of high-order fairness is that fairness is morally significant in itself only regarding what matters – individual well-being – and when it matters – in interpersonal conflicts in which constitutive aspects of individual well-being clash. Consequently, the proposed theory is not exposed to the claim that fairness comes at the expense of welfare. This theory is considered within a consequential framework, based on the standard version and, alternatively, on a novel interpretation of consequentialism. Thus, it refutes the claim that consequentialism does not take the distinction between persons seriously.