In this paper, I will develop a set of boulesic-doxastic tableau systems and prove that they are sound and complete. Boulesic-doxastic logic consists of two main parts: a boulesic part and a doxastic part. By ‘boulesic logic’ I mean ‘the logic of the will’, and by ‘doxastic logic’ I mean ‘the logic of belief’. The first part deals with ‘boulesic’ concepts, expressions, sentences, arguments and theorems. I will concentrate on two types of boulesic expression: ‘individual x wants it to be (...) the case that’ and ‘individual x accepts that it is the case that’. The second part deals with ‘doxastic’ concepts, expressions, sentences, arguments and theorems. I will concentrate on two types of doxastic expression: ‘individual x believes that’ and ‘it is imaginable to individual x that’. Boulesic-doxastic logic investigates how these concepts are related to each other. Boulesic logic is a new kind of logic. Doxastic logic has been around for a while, but the approach to this branch of logic in this paper is new. Each system is combined with modal logic with two kinds of modal operators for historical and absolute necessity and predicate logic with necessary identity and ‘possibilist’ quantifiers. I use a kind of possible world semantics to describe the systems semantically. I also sketch out how our basic language can be extended with propositional quantifiers. All the systems developed in this paper are new. (shrink)

Following a long-standing philosophical tradition, impartiality is a distinctive and determining feature of moral judgments, especially in matters of distributive justice. This broad ethical tradition was revived in welfare economics by Vickrey, and above all, Harsanyi, under the form of the so-called Impartial Observer Theorem. The paper offers an analytical reconstruction of this argument and a step-wise philosophical critique of its premisses. It eventually provides a new formal version of the theorem based on subjective probability.

The rational choice paradigm has proved to be a fruitful means of analysis and explanation in various disciplines concerned with questions of practical rationality, but in various attempts to extend its fields of application the deficiencies of the original account of rational choice have become evident. This paper tries to give a systematic overview of ways in which the rational choice paradigm can be extended and modified.

The purpose of this paper is to show how some of the controversial questions concerning utilitarianism can be clarified by the modelling techniques and the other analytical tools of decision theory (and, sometimes, of game theory). It is suggested that the moral rules of utilitarian ethics have a logical status similar to that of the normative rules (theorems) of such formal normative disciplines as decision theory and game theory.The paper argues that social utility should be defined, not in hedonistic or (...) in ideal-utilitarian terms, but rather in terms of individual preferences, in accordance with the author's equiprobability model of moral value judgments. (shrink)

Rationality and reasonableness are often sharply distinguished from one another and are even held to be in conflict. On this construal, rationality consists in means-end calculation of the most efficient means to one's ends (which are usually taken to be self-interested), while reasonableness consists in equitableness whereby one respects the rights of other persons as well as oneself. To deal with this conflict, it is noted that both rationality and reasonableness are based on reason, which is analyzed as the power (...) of attaining truth, and especially necessary truth. It is then shown that, by the rationality involved in reason, the moral principle of reasonableness, the Principle of Generic Consistency (PGC), has a stringently rational justification in that to deny or violate it is to incur self-contradiction. Objections are considered bearing on relevance and motivation. It is concluded that, where reasonableness and egoistic rationality conflict, the former is rationally superior. (shrink)

Humeans claim that all motivation is by desire. Anti-Humeans maintain that some beliefs can motivate all by themselves. This dispute, I argue, hinges on the question whether belief can rationalize motivation. Moreover, I argue belief can rationalize motivation since rationality requires that one be motivated to φ if one believes one has most reason to φ, and it is possible to be motivated to φ because one believes one has most reason to φ and one exercises one's capacity for rational (...) agency. (shrink)