This article provides a comprehensive review of multiple imputation (MI), a technique for analyzing data sets with missing values. Formally, MI is the process of replacing each missing data point with a set of m > 1 plausible values to generate m complete data sets. These complete data sets are then analyzed by standard statistical software, and the results combined, to give parameter estimates and standard errors that take into account the uncertainty due to the missing data values. This article introduces the idea behind MI, discusses the advantages of MI over existing techniques for addressing missing data, describes how to do MI for real problems, reviews the software available to implement MI, and discusses the results of a simulation study aimed at finding out how assumptions regarding the imputation model affect the parameter estimates provided by MI.

One of the most important developments in modern moral philosophy is the resurgence of interest in the virtues. This book explores two important hopes for such an approach to moral thought: that starting from the virtues should cast light on what makes an action right, and that notions like character, virtue, and vice should yield a plausible picture of human psychology. The book argues that the key to each of these hopes is an understanding of the cognitive and deliberative skills involved in the virtues. If right action is defined in terms of acting generously or kindly, then these virtues must involve skills for determining what the kind or generous thing to do would be on a given occasion. The book also argues that understanding virtuous action as the intelligent pursuit of virtuous goals yields a promising picture of the psychology of virtue. On the whole, this book develops an Aristotelian account of the virtue of practical intelligence or phronesis — an excellence of deliberating and making choices — and argues that phronesis is a necessary part of every virtue. This emphasis on the roots of the virtues in the practical intellect contrasts with ambivalence about the practical intellect in much recent work on the virtues. This book also examines issues like the unity of the virtues, responsibility for character, and “the virtuous person”.

This introductory chapter begins by exploring the nature of pleasure at a common-sense level. It then shows what sorts of questions we need a more theoretically complete and rigorous account of pleasure to answer, and provides a brief overview of how Plato addresses them.

This chapter sets forth the main aim of the book, viz. to argue that virtue ethics cannot survive without the thesis that phronesis, much as Aristotle conceived of it, is a crucial part of all the virtues, and that this thesis is defensible and attractive. It examines Aristotle's account of deliberation and phronesis in some detail. The chapter concludes by summarizing some of the main contemporary controversies surrounding the view that phronesis is necessary for virtue.

This book examines Plato's subtle and insightful analysis of pleasure and explores its intimate connections with his discussions of value and human psychology. The book offers a fresh perspective on how good things bear on happiness in Plato's ethics, and shows that for Plato, pleasure cannot determine happiness because pleasure lacks a direction of its own. Plato presents wisdom as a skill of living that determines happiness by directing one's life as a whole, bringing about goodness in all areas of one's life, as a skill brings about order in its materials. The ‘materials’ of the skill of living are, in the first instance, not things like money or health, but one's attitudes, emotions, and desires where things like money and health are concerned. Plato recognizes that these ‘materials’ of the psyche are inchoate, ethically speaking, and in need of direction from wisdom. Among them is pleasure, which Plato treats not as a sensation but as an attitude with which one ascribes value to its object. However, Plato also views pleasure, once shaped and directed by wisdom, as a crucial part of a virtuous character as a whole. Consequently, Plato rejects all forms of hedonism, which allows happiness to be determined by a part of the psyche that does not direct one's life but is among the materials to be directed. At the same time, Plato is also able to hold both that virtue is sufficient for happiness, and that pleasure is necessary for happiness, not as an addition to one's virtue, but as a constituent of one's whole virtuous character itself. Plato therefore offers an illuminating role for pleasure in ethics and psychology, one to which we may be unaccustomed: pleasure emerges not as a sensation or even a mode of activity, but as an attitude — one of the ways in which we construe our world — and as such, a central part of every character.