Online research in philosophy

One of the most significant disputes in early modern philosophy was between the moral rationalists and the moral sentimentalists. The moral rationalists — such as Ralph Cudworth, Samuel Clarke and John Balguy — held that morality originated in reason alone. The moral sentimentalists — such as Anthony Ashley Cooper, the third Earl of Shaftesbury, Francis Hutcheson and David Hume — held that morality originated at least partly in sentiment. In addition to arguments, the rationalists and sentimentalists developed rich analogies. The most significant analogy the rationalists developed was between morality and mathematics. The most significant analogy the sentimentalists developed was between morality and beauty. These two analogies illustrate well the main ideas, underlying insights, and accounts of moral phenomenology the two positions have to offer. An examination of the two analogies will thus serve as a useful introduction to the debate between moral rationalism and moral sentimentalism as a whole.

Moral rationalism is the view that morality originates in reason alone. It is often contrasted with moral sentimentalism, which is the view that the origin of morality lies at least partly in (non-rational) sentiment. The eighteenth century saw pitched philosophical battles between rationalists and sentimentalists, and the issue continues to fuel disputes among moral philosophers today.

This paper concerns the normative status of coherence of desires, in the context of moral rationalism. I argue that 'desiderative coherence' is not tied to rationality, but is rather of pragmatic, instrumental, and sometimes moral value. This means that desire-based views cannot rely on coherence to support non-agent-relative accounts of moral reasons. For example, on Michael Smith's neo-rationalist view, you have 'normative reason' to do whatever your maximally coherent and fully informed self would want you to do, whether you want to do it or not. For these reasons to be non-agent-relative, coherence would have to be grounded in rationality, but I argue that it is not. I analyze, and reject, various strategies for establishing a coherence-rationality connection, considering in detail a purported analogy between desires and a priori beliefs, with particular attention to the case of mathematics.

The Ideal of a Rational Morality collects the most important essays by the distinguished moral philosopher Marcus G. Singer. Its guiding theme is the concept of a morality based in reason, which is presupposed in ordinary moral contexts and provides an ideal for improving ordinary morality and correcting moral judgements. Singer makes compelling claims that certain fundamental presuppositions are inescapable in moral thought, that fundamental moral principles can be proved, and that the concepts of truth and 'common sense' are essential to ethics.

With the rapid recent growth of naturalized metaethics, Richard Joyce’s paper sounds an appropriate cautionary note. It’s easy to be overwhelmed by sexy new data and to neglect the difficulties in using the data to draw major philosophical conclusions. One of the central views in the sights of naturalists has been moral rationalism. Jonathan Haidt (2001), Joshua Greene (this volume), Jesse Prinz (forthcoming), and I (2002, 2004b) have all used recent empirical findings to challenge moral rationalist views. Although Joyce is not himself a moral rationalist (see Joyce 2002), he deftly works to beat back our attacks on moral rationalism. Here my goal is to uphold the view that empirical work can challenge moral rationalism in the aftermath of Joyce’s insightful discussion.

To reject a false theory on the basis of an unsound argument is, in my opinion, as much an intellectual sin as to embrace a false theory. Thus, although I am no fan of any particular form of moral rationalism—and, indeed, on occasion have gone out of my way to criticize it—when rationalism is assailed for faulty reasons I find myself in the curious position of leaping to its defense (which goes to show that in philosophy it isn’t the case that one’s enemy’s enemy is one’s friend). This puts me at something of a dialectical disadvantage, since my “defense” of moral rationalism has strict limits: I will defend it against specific kinds of criticism, but I have no interest in defending it simpliciter. It is important to bear in mind that what is in dispute between Shaun Nichols and myself is not the truth or falsity of moral rationalism, but rather what kind of evidence bears on the matter.

I argue that we should reject all traditional forms of act-consequentialism if moral rationalism is true. (Moral rationalism, as I define it, holds that if S is morally required to perform x, then S has decisive reason, all things considered, to perform x.) I argue that moral rationalism in conjunction with a certain conception of practical reasons (viz., the teleological conception of reasons) compels us to accept act-consequentialism. I give a presumptive argument in favor of moral rationalism. And I argue that act-consequentialism is best construed as a theory that ranks outcomes, not according to their impersonal value, but according to how much reason each agent has to desire that they obtain.

Psychopaths are renowned for their immoral behavior. They are ideal candidates for testing the empirical plausibility of moral theories. Many think the source of their immorality is their emotional deficits. Psychopaths experience no guilt or remorse, feel no empathy, and appear to be perfectly rational. If this is true, sentimentalism is supported over rationalism. Here, I examine the nature of psychopathic practical reason and argue that it is impaired. The relevance to morality is discussed. I conclude that rationalists can explain the moral deficits of psychopaths as well as sentimentalists. In the process, I identify psychological structures that underpin practical rationality.

It is often claimed that the existence of psychopaths undermines moral rationalism. I examine a recent empirically based argument for this claim and conclude that rationalist accounts of moral judgement and moral reasoning are perfectly compatible with the evidence cited.