Recent years have seen several high-quality edited volumes on John Stuart Mill's moral and political philosophy. But a number of new single-author studies of Mill's work remind us that our understanding of how the pieces of his moral and political philosophy hold together has benefited especially from the sort of synthesizing treatment found in book form. Dale E. Miller's contribution evokes the best of this tradition, offering a unified and carefully argued account that deserves to be a cornerstone of Mill studies for years to come.

This book also has two virtues that make it an excellent entry into many of the main issues arising from Mill. First, Miller's writing is extremely clear and direct. Second, he often sets his own preferred interpretation against charitably presented rival accounts, freely admitting when the textual evidence is ambiguous and clearly explaining his philosophical or interpretative grounds for preferring one reading over another.

Miller's book is organized into four parts. Part I contains a biographical chapter and a brief overview of Mill's empiricism and his associationist views on psychology. Part II addresses major disputes concerning Mill's moral philosophy. Part III covers Mill's political philosophy, including his liberalism, his normative political economy and his defence of representative democracy. Part IV concludes with a comment on the place of Mill's optimism about progress in the contemporary world. In what follows I address what I found to be the most distinctive and worthwhile aspects of these chapters, but of course a great deal of interest must be left out of a short review.

I will not linger on part I (chs. 1–2), but it contains the most sensible short summary I have seen of the stages of Mill's career, his major influences (especially Harriett Taylor Mill) and his core methodological approach. In particular, chapter 1 reminds us that it is easy to overstate the effect of Mill's youthful ‘mental crisis’ on his philosophical commitments and that, despite influences from disparate quarters, he remained firmly in the utilitarian camp. Chapter 2 highlights his account of the formation of character, and especially the training of our moral emotions. This latter concern plays an important role in Miller's rule-utilitarian interpretation of Mill's moral theory in chapter 6, which is the heart of the book.

Part II comprises four chapters (chs. 3–6) addressing Mill's hedonism and his ‘proof’ of the principle of utility, his theory of higher- and lower-quality pleasures, the distinction between act- and rule-utilitarianism, and Miller's preferred rule-utilitarian interpretation called ‘internal sanction’ utilitarianism (p. 94). In chapters 3 and 4 Miller examines Mill's conception of happiness as the only thing of intrinsic value. In the course of defending a hedonist interpretation, he effectively explains away passages suggesting that, on Mill's view, we can desire things other than pleasure as ends. In order to accommodate Mill's account of higher-quality pleasures, Miller opts for an ‘externalist’ interpretation of his hedonism, according to which pleasure is cashed out as any subjective experience towards which we have an appropriate pro-attitude (p. 35). His introduction of the ‘decided preference test’ of higher-quality pleasures is excellent. In particular, he correctly rejects the reading according to which the test asserts that even ‘the smallest amount of a [higher] pleasure is always more valuable than the greatest amount of any other pleasure of lower quality’ (p. 58).

In chapters 5 and 6, Miller defends a sophisticated psychological variant of David Lyons's sanction-based interpretation of Mill's utilitarianism. Having laid out competing textual evidence for act- and rule-utilitarian interpretations – he is admirably clear about what distinguishes these positions – Miller argues that a rule-utilitarian reading is required by Mill's claim that ‘x is wrong’ implies that punishment, and especially guilt feelings, would be appropriate for doing x. Recent scholarship has tended towards a rule-utilitarian interpretation of Mill's moral theory, and Miller's is the best single articulation of where that tendency has led. In brief, Miller argues that because judgements about the appropriateness of guilt are regulated by ‘conscience’, which is a rule-bound psychological faculty (that is, it is constituted by ‘internalized’ rules for governing behaviour), judgements about wrongness are rule-bound. The principle of utility is applied at the level of those rules that it would be optimal to have internalized or enforced by conscience – Miller's is an ‘ideal code’ interpretation – and then the psychological contours of conscience make it that it could be wrong to violate one of those rules even when happiness would be maximized by the violation: ‘when your conscience is enforcing a rule you cannot just set the rule aside’ (p. 92).

A full discussion of Miller's argument is not possible here, but reading Mill as a rule-utilitarian is, I believe, an error. Admittedly, it has some advantages. Most notably it provides a means for making Mill's defence of individual rights more robust than might seem possible on an act-utilitarian interpretation. But the textual evidence is not as ambiguous as is often suggested. Key textual support, such as the ‘the case of abstinences’ (p. 90), allows for sophisticated act-utilitarian interpretation once one allows that ‘consequences in the particular case’ refers only to local consequences. And Mill never claims that one ought to follow a rule when one knows that violating the rule would better promote utility and one is capable of performing the action. Moreover, he makes clear in his Logic that morality is a system of merely general (not universal) rules summarizing in a handy practical form the relevant underlying sciences. Even the optimal set of rules, based on a complete science, would allow for exceptions in unusual circumstances. And although Mill ties ‘moral wrongness’ to the appropriateness of punishment, the fact that conscience may, as a psychological matter, be rule-bound in the way Miller suggests tells us nothing about whether the pangs of conscience are appropriately felt in a given instance. Mill writes that a person ‘cannot discharge himself from moral responsibility by pleading that he had the general rule in his favour’ (‘Taylor's Statesman’, co-authored with George Grote, Collected Works, vol. 19, p. 640). Whether or not these points are correct, anyone grappling with the question of Mill's rule-utilitarianism must grapple with Miller's state-of-the-art discussion.

Along the way, Miller also makes an invaluable point concerning Mill's ‘Art of Life’, with its departments of Prudence, Morality and Aesthetics – namely, that ‘Prudence’ concerns expediency (or overall actual utility) and not one's own best self-interest, as the name might suggest (p. 81). Note, however, that on Miller's view, if Prudence concerns overall actual utility and Morality concerns the rules that it would be optimal to internalize in society, they each invoke a competing objective standard equally inaccessible to limited practical agents. It makes more sense, I believe, to associate Morality with Mill's theory of blameworthiness, which is relative to the limited epistemic, emotional and physical circumstances of particular practical agents, leaving Prudence as the department of objective choiceworthiness.

In part III, on Mill's political philosophy, Miller first takes on familiar puzzles about the liberty principle, especially its conception of ‘harm’. In chapter 7, he argues that ‘harm’ is constituted by damage to certain interests – that might be considered primary goods – below some ‘baseline level’ (p. 143; see also pp. 120–1, 144). This account of harm enjoys little direct textual support – it is much more restricted than many of Mill's formulations of the liberty principle would suggest – but in the face of long-standing difficulties on this score Miller charitably tries to articulate a liberty principle that, all on its own, might secure a large sphere of individual liberty. While I am sympathetic to the impulse, I think such a restricted conception of ‘harm’ obscures Mill's overall defence of liberty. Miller's discussion of Mill's account of the value of freedom (pp. 132–41) is excellent, however, and chapter 8 on Mill's normative political economy clears important ground on substantive issues, including his views on socialism. Chapter 9 on representative democracy provides an excellent overview of Mill's distinctive positions such as plural voting and proportional representation, but fails to my mind to make headway in explaining how he weighs various considerations in constructing those institutional designs and so also fails to follow through on Miller's own suggestion that the criteria Mill appeals to in his defence of representative democracy might be applied to his proposed reforms to capitalism and his case for individual liberty (p. 172).

I have necessarily passed over a number of places where Miller provides valuable correctives to problems in the secondary literature and otherwise helps to clarify key interpretative issues concerning Mill's moral and political philosophy. Whatever problems remain, Miller's book is essential reading for anyone interested in the frontline of Mill scholarship.