Moral Psychology with Nietzsche by Brian Leiter (review)

Brian Leiter's Moral Psychology with Nietzsche draws together seven of his previous papers (one coauthored with Joshua Knobe), expands and updates them, and weaves them together into a unified naturalist line of interpretation. The fundamental positions largely remain the same. The reader already familiar with Leiter's work will thus not be in for major surprises, but will have much to learn from reading the new exegetical and philosophical details in this book.

The "moral psychology" indicated in the book's title is construed very broadly to encompass, for example, metaethics in addition to the more familiar questions one might associate with moral psychology. While the book defends and challenges interpretive theses on Nietzsche's work at a number of points, it, as its title indicates, is primarily not a work of Nietzsche interpretation, but instead an attempt to use Nietzsche as a point of departure to think about the underlying philosophical issues, to "articulate and defend [a] moral psychology in a Nietzschean spirit" (14). Leiter is admirably forthright about this orientation, in a way that should serve as a model for others. There are a number of points, textual and philosophical, where I was not persuaded by his case, but the clarity of its presentation leaves one in the refreshing position of having the terms of debate clearly demarcated. As with Leiter's work generally, it is engagingly written and philosophically adroit.

The guiding methodological thread across these chapters is naturalism (2–11), of the form that Leiter put forward in his 2002 book Nietzsche on Morality (London: Routledge, 2002) and has defended since. The present book applies that naturalism to thinking about metaethics, epistemology, philosophy of action, and some more familiar issues in moral psychology (such as character, reactive attitudes, and the relation between affects and moral judgment). The title is, to my ear, thus somewhat misleading given the range of material here. Naturalistic Philosophy with Nietzsche might have better represented the breadth of contents. It is now widely agreed that Nietzsche is a naturalist of some kind, as, for instance, an opponent of supernaturalist metaphysics. Leiter has defended the more specific interpretation that Nietzsche is what he calls an "M-naturalist," one offering and prizing "speculative" philosophical theories that seek to have "continuity with the methods of successful sciences" (2). One idea throughout the book is that Nietzsche anticipates what will be lent further credibility by later psychological investigation, for example, work from Wegner and Libet on willing (141–42) or psychological research about the connection between behavior and avowed attitudes (176–77). As an astute observer of human beings and as a keen, if idiosyncratic, reader of the science of his time, Nietzsche, Leiter contends, formed hypotheses, which have since garnered further empirical support.

The first main section of Leiter's book concerns the metaphysics and epistemology of value, and the position attributed to Nietzsche and defended is a form of antirealism about such value. This is the focus of chapters 1 and 2. As Leiter reconstructs Nietzsche's position, Nietzsche reaches this skeptical conclusion through an abductive argument from disagreement. The best conclusion to reach in the face of intractable disagreement among moral philosophers is that there are no "objective moral facts or facts about reasons for acting" (32). Leiter criticizes what he calls "privilege" readings of Nietzsche, those that see him holding that certain values (e.g., power) have a genuine authority or standing. Leiter's Nietzsche rejects the idea of such values. Therefore, "at bottom, Nietzsche," on Leiter's reading, "has nothing to say to those readers who don't share his evaluative tastes" (65). Leiter turns in chapters 3 and 4 to discussing the relation between moral judgments and affects. If we are not tracking objective facts in making moral judgments, what explains how we reach the moral judgments that we do? Affects, feelings, and drives underpin these judgments, and we are to appeal to the former to understand the latter (69–70). Chapter 4 investigates Nietzsche's perspectivism...