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.

Kiesewetter defends the normativity of rationality by presenting a new solution to the problems that arise from the common assumption that we ought to be rational. He provides a defence of a reason-response conception of rationality, an evidence-relative account of reason, and an explanation of structural irrationality in relation to these accounts.

Ralph Wedgwood gives a general account of what it is for states of mind and processes of thought to count as rational. Whether you are thinking rationally depends purely on what is going on in your mind, but rational thinking is a means to the goal of getting things right in your thinking, by believing the truth or making good choices.

Errol Lord offers a new account of the nature of rationality: what it is for one to be rational is to correctly respond to the normative reasons one possesses. Lord defends novel views about what it is to possess reasons and what it is to correctly respond to reasons, and dispels doubts about whether we ought to be rational.

This is a review, by Sebastian Schmidt, of Ralph Wedgwood's The Value of Rationality (Oxford University Press, 2017).

Recent views of reasons and rationality make it plausible that it can sometimes be rational to do what you have no reason to do. A number of writers have concluded that if this is so, rationality is not normative. But this is a mistake. Even if we assume a tight connection between reasons and normativity, the normativity of rationality does not require that there is always reason to be rational. The first half of this paper illustrates this point with reference (...) to the subjective reasons account of rationality. The second half suggest that this point may have been missed because of certain similarities between the subjective reasons account and the importantly different transparency account. On the transparency account, rationality seems not to be normative. I think it is often assumed that what goes for the transparency account goes for the subjective reasons account as well. But I argue that this is a mistake. A corollary is that the subjective reasons account has an important advantage over the transparency account, given how plausible it is that rationality is normative. (shrink)

John Broome argues that rationality cannot consist in reasons-responsiveness since rationality supervenes on the mind, while reasons-responsiveness does not supervene on the mind. I here defend this conception of rationality by way of defending the assumption that reasons-responsiveness supervenes on the mind. Given the many advantages of an analysis of rationality in terms of reasons-responsiveness, and in light of independent considerations in favour of the view that reasons-responsiveness supervenes on the mind, we should take seriously the backup view, a hypothesis (...) that explains why reasons-responsiveness supervenes on the mind even though paradigmatic reasons are external facts. I argue that Broome’s objections to the backup view, as well as his more general objection to the thesis that reasons-responsiveness supervenes on the mind, do not succeed. (shrink)

ABSTRACT Philosophers often do not make as sharp a distinction as they should between rationality and normativity. Partly this is because the word ‘reason’ can be used to refer to either, and this leads to a confusion over meanings. This paper starts by clarifying the meanings of ‘normativity’ and ‘rationality’. It argues that it is a conceptual truth that rationality supervenes on the mind. Then it considers substantive arguments that purport to show there is no real distinction between rationality and (...) normativity. Many philosophers give a reductive account of rationality in terms of reasons. In particular, many claim that rationality consists in responding correctly to reasons. Since responding correctly to reasons is the concern of normativity, this in effect identifies rationality with normativity. This paper denies that rationality is identical to normativity, by means of what I call a ‘quick objection’. The quick objection is that rationality supervenes on the mind whereas complying with normativity does not. I consider and reject some ways of responding to the quick objection, including an argument by Kiesewetter to the effect that normativity supervenes on the mind and one by Lord to the effect that rationality does not. I also consider a different, Kantian argument to the effect that rationality does not supervene on the mind. (shrink)

Derek Parfit presents the third volume of On What Matters, his landmark work of moral philosophy. Parfit develops further his influential treatment of reasons, normativity, the meaning of moral discourse, and the status of morality. He engages with his critics, and shows the way to resolution of their differences.

My dissertation is a systematic defense of the claim that what it is to be rational is to correctly respond to the reasons you possess. The dissertation is split into two parts, each consisting of three chapters. In Part I--Coherence, Possession, and Correctly Responding--I argue that my view has important advantages over popular views in metaethics that tie rationality to coherence (ch. 2), defend a novel view of what it is to possess a reason (ch. 3), and defend a novel (...) view about what it is to act and hold attitudes for normative reasons (ch. 4). In Part II--Foundationalism, Deception, and The Importance of Being Rational--I argue that foundationalists about epistemic rationality should think that the foundational beliefs are held for sufficient reasons (ch. 5), argue that my view solves the New Evil Demon problem for externalism (and solves a related and underapprieciated problem) (ch. 6), and argue that my view can vindicate the thought that we ought to be rational (ch. 7). (shrink)