I show that David Lewis’s principal principle is not preserved under Jeffrey conditionalization. Using this observation, I argue that Lewis’s reason for rejecting the desire as belief thesis and Adams’s thesis applies also to his own principal principle. 1 Introduction2 Adams’s Thesis, the Desire as Belief Thesis, and the Principal Principle3 Jeffrey Conditionalization4 The Principal Principles Not Preserved under Jeffrey Conditionalization5 Inadmissible Experiences.

A triviality result for what Lewis called “the Desire by Necessity Thesis” and Broome : 265–267, 1991) called “the Desire as Expectation Thesis” is presented. The result shows that this thesis and three other reasonable conditions can be jointly satisfied only in trivial cases. Some meta-ethical implications of the result are discussed. The discussion also highlights several issues regarding Lewis ’ original triviality result for “the Desire as Belief Thesis” that have not been properly understood in the literature.

I argue that desire sometimes amounts to knowledge, in the same sense that belief sometimes amounts to knowledge. The argument rests on two assumptions: that goodness is the correctness condition for desire and that knowledge is apt mental representation. Desire that amounts to knowledge—or ‘conative knowledge’—is illustrated by cases in which someone knows the goodness of something despite not believing that it is good.

This paper argues that practical reasoning is a mental process which leads a person from a set of existent mental states to an intention. In Section 1, I defend this view against two other proposals according to which practical reasoning either concludes in an action itself or in a normative belief. Section 2 discusses the correctness of practical reasoning and explains how the correctness of instrumental reasoning can be explained by the logical relations that hold between the contents of the (...) mental states. In Section 3, I explore the correctness of normative practical reasoning. I conclude with the sceptical view that correct practical reasoning cannot require us to intend to do what we believe we ought to do. (shrink)

The thesis explores the question of how should a rational moral agent reason and make choices when he finds himself accepting inconsistent moral judgments. It is argued that it is both conceptually and psychologically justified to describe such an agent as suffering from uncertainty. Such uncertainty, however, is not uncertainty regarding the truth of some descriptive claim, but rather uncertainty regarding the truth of a normative claim. Specifically it is uncertainty regarding the truth of a moral judgement. In the literature (...) this is sometimes called “moral uncertainty”. Two different lines of philosophical literatures that explore the idea of moral uncertainty are discussed. The first line – the one that originated from David Lewis‟ argument against the “Desire as Belief Thesis” – explores the mere possibility of moral uncertainty, while the second line explores the question how ought a rational moral agent choose in face of moral uncertainty. The discussion of these two lines of research leads to the conclusion that a consistent account of moral decision making under conditions of moral uncertainty that will be applicable to the kind of cases that the thesis explores, must make use of degrees of beliefs in comparative moral judgements and of them alone. Specifically, no references to degrees of moral value should be made. An attempt to present such an account in the framework of an extension of Leonard Savage‟s model for decision making is carried out. This attempt leads to a problematic result. Several implications of the result to ethic and meta-ethics are discussed as well as possible ways to avoid it. The conclusion is partly positive and partly negative: While a plausible account of moral decision making under conditions of moral uncertainty is presented, an account of moral reasoning that aims at finding a complete moral theory is shown to be a very difficult – if not impossible - aim to achieve. (shrink)

The paper discusses the notion of reasoning with comparative moral judgements (i.e judgements of the form “act a is morally superior to act b”) from the point of view of several meta-ethical positions. Using a simple formal result, it is argued that only a version of moral cognitivism that is committed to the claim that moral beliefs come in degrees can give a normatively plausible account of such reasoning. Some implications of accepting such a version of moral cognitivism are discussed.

Two plausible claims seem to be inconsistent with each other. One is the idea that if one reasonably believes that one ought to fi, then indeed, on pain of acting irrationally, one ought to fi. The other is the view that we are fallible with respect to our beliefs about what we ought to do. Ewing’s Problem is how to react to this apparent inconsistency. I reject two easy ways out. One is Ewing’s own solution to his problem, which is (...) to introduce two different notions of ought. The other is the view that Ewing’s Problem rests on a simple confusion regarding the scope of the ought-operator. Then, I discuss two hard ways out, which I label objectivism and subjectivism, and for which G.E. Moore and Bishop Butler are introduced as historical witnesses. These are hard ways out because both of these views have strong counterintuitive consequences. After explaining why Ewing’s Problem is so difficult, I show that there is conceptual room in-between Moore and Butler, but I remain sceptical whether Ewing’s Problem is solvable within a realist framework of normative facts. (shrink)