Online research in philosophy

Motivational internalism about moral judgements is the plausible view that accepting a moral judgement is necessarily connected to motivation motivation. However, it conflicts with the Humean theory that motives must be constituted by desires. Simple versions of internalism run into problems with people who do not desire to do what they believe right. This has long been urged by David Brink. Hence, many internalists have adopted more subtle defeasible views, on which only rational agents will have a desire to act. I will argue that more complex versions run into problems with self-effacing values of the sort Parfit highlights in another context. Such values can only be attained indirectly. After proposing a general account of motivation suited to the internalist thesis, I argue that Anti-Humeanism is better suited to accommodating the internalist insight.

Debate between Humean contingentists and anti-Humean necessitarians in the philosophy of science is ongoing. One of the most important contemporary anti-Humeans is Alexander Bird. Bird calls the particular version of Humeanism he is opposed to 'categoricalism'. In his paper (2005) and in Chapter 4 of his book (2007) Bird argues against categoricalism about properties and laws. His arguments against categoricalism about properties are intended to support the necessitarian position he calls dispositional monism. His arguments against categoricalism about laws are intended to refute the contingent regularity view of laws (even in its sophisticated Lewisean version) and the nomic necessitation view of Armstrong (which involves a contingent necessitation relation). The general position Bird defends is that properties are necessarily related to the dispositions they bestow on their bearers and laws are necessary truths. I consider two of Bird's arguments against categoricalism about properties, and one of his arguments against the regularity view of laws. Maybe other arguments against categoricalism are persuasive. These, I submit, are not.

Motivational internalism about moral judgments is the plausible view that accepting a moral judgment is necessarily connected to motivation motivation. However, it conflicts with the Humean theory that motives must be constituted by desires. Simple versions of internalism run into problems with people who do not desire to do what they believe right. This has long been urged by David Brink. Hence, many internalists have adopted more subtle defeasible views, on which only rational agents will have a desire to act. I will argue that more complex versions run into problems with self-effacing values of the sort Parfit highlights in another context. Such values can only be attained indirectly. After proposing a general account of motivation suited to the internalist thesis, I argue that Anti-Humeanism is better suited to accommodating the internalist insight.

Realists about practical reasons agree that judgments regarding reasons are beliefs. They disagree, however, over the question of how such beliefs motivate rational action. Some adopt a Humean conception of motivation, according to which beliefs about reasons must combine with independently existing desires in order to motivate rational action; others adopt an anti-Humean view, according to which beliefs can motivate rational action in their own right, either directly or by giving rise to a new desire that in turn motivates the action. I argue that the realist who adopts a Humean model for explaining rational action will have a difficult time giving a plausible account of the role that desire plays in this explanation. I explore four interpretations of this role and argue that none allows a Humean theory to explain rational action as convincingly as an anti-Humean theory does. The first two models, in different ways, make acting on a reason impossible. The third allows this possibility, but only by positing a reason-sensitive desire that itself demands an explanation. The fourth avoids this explanatory challenge only by retreating to an empty form of the Humean view. In contrast, an anti-Humean theory can provide an intuitively plausible explanation of rational action. I conclude that the realist about reasons should adopt an anti-Humean theory to explain rational action.

On Hume’s account of motivation, beliefs and desires are very di¤erent kinds of propositional attitudes. Beliefs are cognitive attitudes, desires emotive ones. An agent’s belief in a proposition captures the weight he or she assigns to this proposition in his or her cognitive representation of the world. An agent’s desire for a proposition captures the degree to which he or she prefers its truth, motivating him or her to act accordingly. Although beliefs and desires are sometimes entangled, they play very di¤erent roles in rational agency.1 In two classic papers (Lewis 1988, 1996), David Lewis discusses several challenges to this Humean picture, but ultimately rejects them. We think that his discussion of a central anti-Humean alternative – the desire-as-belief thesis – is in need of re…nement. On this thesis, the desire for proposition p is given by the belief that p is desirable. Lewis claims that ‘[e]xcept in trivial cases, [this thesis] collapses into contradiction’(Lewis 1996, p. 308). The problem, he argues, is that the thesis is inconsistent with the purportedly plausible requirement that one’s desire for a proposition should not change upon learning that the proposition is true; call this the invariance requirement. In this paper, we revisit Lewis’s argument. We show that, if one carefully distinguishes between non-evaluative and evaluative propositions, the desire-asbelief thesis can be rendered consistent with the invariance requirement. Lewis’s conclusion holds only under certain conditions: the desire-as-belief thesis con- ‡icts with the invariance requirement if and only if there are certain correlations between non-evaluative and evaluative propositions. But when there are such correlations, we suggest, the invariance requirement loses its plausibility. Thus Lewis’s argument against the desire-as-belief thesis appears to be valid only in cases in which it is unsound.

In the opening chapter of What We Owe To Each Other, Tim Scanlon produces a sustained critique of a Humean conception of practical reason. Scanlon claims he will argue that unless having a desire just is to see something as a reason, desires play (almost) no role in the explanation or justification of action. Yet his specific arguments against Humeanism all employ a very austere understanding of desire (which he calls the "standard model"), and attempt to show that desires so understood are not up to any explanatory or justificatory task. Since the standard model represents only one understanding of desire (distinct from the "recognition of reasons") his specific arguments cannot establish his stated general thesis. I show how a more robust conception of desire will leave the Humean account safe from Scanlon's specific arguments.

In 'The Humean Theory of Motivation' Michael Smith attempts two tasks: he offers an account of the debate about motivation between Humeans and anti-Humeans and he provides arguments that are designed to show that the Humeans win. While the paper is of great virtue in clarifying the debate, I believe that it falls short of both its goals. It does not highlight the really central issue between Humeans and anti-Humeans and it does not provide arguments which would settle that issue in favour of the Humean side.

David Lewis [1988; 1996] canvases an anti-Humean thesis about mental states: that the rational agent desires something to the extent that he or she believes it to be good. Lewis offers and refutes a decision-theoretic formulation of it, the 'Desire-as-Belief Thesis'. Other authors have since added further negative results in the spirit of Lewis's. We explore ways of being anti-Humean that evade all these negative results. We begin by providing background on evidential decision theory and on Lewis's negative results. We then introduce what we call the indexicality loophole: if the goodness of a proposition is indexical, partly a function of an agent's mental state, then the negative results have no purchase. Thus we propose a variant of Desire-as-Belief that exploits this loophole. We argue that a number of meta-ethical positions are committed to just such indexicality. Indeed, we show that with one central sort of evaluative belief--the belief that an option is right--the indexicality loophole can be exploited in various interesting ways. Moreover, on some accounts, 'good' is indexical in the same way. Thus, it seems that the anti-Humean can dodge the negative results.

David Lewis [1988; 1996] canvases an anti-Humean thesis about mental states: that the rational agent desires something to the extent that he or she believes it to be good. Lewis offers and refutes a decision-theoretic formulation of it, the `Desire-as- Belief Thesis'. Other authors have since added further negative results in the spirit of Lewis's. We explore ways of being anti-Humean that evade all these negative results. We begin by providing background on evidential decision theory and on Lewis's negative results. We then introduce what we call the indexicality loophole: if the goodness of a proposition is indexical, partly a function of an agent's mental state, then the negative results have no purchase. Thus we propose a variant of Desire-as- Belief that exploits this loophole. We argue that a number of meta-ethical positions are committed to just such indexicality. Indeed, we show that with one central sort of evaluative beliefÐthe belief that an option is rightÐthe indexicality loophole can be exploited in various interesting ways. Moreover, on some accounts, `good' is indexical in the same way. Thus, it seems that the anti-Humean can dodge the negative results.

David Lewis claims that a simple sort of anti-Humeanism-that the rational agent desires something to the extent he believes it to be good-can be given a decision-theoretic formulation, which Lewis calls 'Desire as Belief' (DAB). Given the (widely held) assumption that Jeffrey conditionalising is a rationally permissible way to change one's mind in the face of new evidence, Lewis proves that DAB leads to absurdity. Thus, according to Lewis, the simple form of anti-Humeanism stands refuted. In this paper we investigate whether Lewis's case against DAB can be strengthened by examining how it fares under rival versions of decision theory, including other conceptions of rational ways to change one's mind. We argue that the anti-Humean may escape Lewis's argument either by adopting a version of causal decision theory, or by claiming that the refutation only applies to hyper-idealised rational agents, or by denying that the decision-theoretic framework has the expressive capacity to formulate anti-Humeanism.