This is a major work in moral philosophy, the long-awaited follow-up to Parfit's 1984 classic Reasons and Persons, a landmark of twentieth-century philosophy. Parfit now presents a powerful new treatment of reasons and a critical examination of the most prominent systematic moral theories, leading to his own ground-breaking conclusion.

There is a debate in normative ethics about whether or not our moral obligations depend solely on either our evidence concerning, or our beliefs about, the world. Subjectivists maintain that they do and objectivists maintain that they do not. I shall offer some arguments in support of objectivism and respond to the strongest argument for subjectivism. I shall also briefly consider the significance of my discussion to the debate over whether one’s future voluntary actions are relevant to one’s current moral (...) obligations. (shrink)

This article proposes a new theory of rational decision, distinct from both causal decision theory (CDT) and evidential decision theory (EDT). First, some intuitive counterexamples to CDT and EDT are presented. Then the motivation for the new theory is given: the correct theory of rational decision will resemble CDT in that it will not be sensitive to any comparisons of absolute levels of value across different states of nature, but only to comparisons of the differences in value between the available (...) options within states of nature; however, the correct theory will also resemble EDT in that it will rely on conditional probabilities (not unconditional probabilities). The new theory gives a prominent role to the notion of a “benchmark” for each state of nature, by comparison with which the value of the available options in that state of nature are measured, and so it has been called the Benchmark Theory (BT). It is argued that BT gives the right verdict on the cases that seem to be counterexamples to CDT and EDT. Finally, some objections to BT are considered and answered. (shrink)

Normativity involves two kinds of relation. On the one hand, there is the relation of being a reason for. This is a relation between a fact and an attitude. On the other hand, there are relations specified by requirements of rationality. These are relations among a person's attitudes, viewed in abstraction from the reasons for them. I ask how the normativity of rationality—the sense in which we ‘ought’ to comply with requirements of rationality—is related to the normativity of reasons—the sense (...) in which we ‘ought’ to have the attitudes what we have conclusive reason to have. The normativity of rationality is not straightforwardly that of reasons, I argue; there are no reasons to comply with rational requirements in general. First, this would lead to ‘bootstrapping’, because, contrary to the claims of John Broome, not all rational requirements have ‘wide scope’. Second, it is unclear what such reasons to be rational might be. Finally, we typically do not, and in many cases could not, treat rational requirements as reasons. Instead, I suggest, rationality is only apparently normative, and the normativity that it appears to have is that of reasons. According to this ‘Transparency Account’, rational requirements govern our responses to our beliefs about reasons. The normative ‘pressure’ that we feel, when rational requirements apply to us, derives from these beliefs: from the reasons that, as it seems to us, we have. (shrink)

Argues for the humean theory of motivation on the grounds that rejecting it requires rejecting decision theory.

Is there any distinctive aspect of rationality that deserves the label of “instrumental rationality”? Recently, Joseph Raz (2005) has argued that instrumental rationality is a “myth”. In this essay, I shall give some qualified support to Raz’s position: as I shall argue, many philosophers have indeed been seduced by certain myths about instrumental rationality. Nonetheless, Raz’s conclusion is too strong. Instrumental rationality is not itself a myth: there really is a distinctive aspect of rationality that deserves the label of “instrumental (...) rationality”. -/- In the first two sections of this essay, I shall start by giving a rough intuitive description of the phenomenon that seems to me the best candidate for the label “instrumental rationality”. As we shall see, this rough description gives us reason to reject some of the myths that surround instrumental rationality. Then in the rest of this essay, I shall try to give a more precise general specification of this phenomenon. In Sections 3 and 4, I shall consider what has been said about instrumental rationality by several other philosophers. Identifying what is missing in these other philosophers’ accounts will help me to develop my own positive specification, which I shall present in Sections 5 and 6. (shrink)