How can the propositional attitudes of several individuals be aggregated into overall collective propositional attitudes? Although there are large bodies of work on the aggregation of various special kinds of propositional attitudes, such as preferences, judgments, probabilities and utilities, the aggregation of propositional attitudes is seldom studied in full generality. In this paper, we seek to contribute to …lling this gap in the literature. We sketch the ingredients of a general theory of propositional attitude aggregation and prove two new theorems. (...) Our …rst theorem simultaneously characterizes some prominent aggregation rules in the cases of probability, judgment and preference aggregation, including linear opinion pooling and Arrovian dictatorships. Our second theorem abstracts even further from the speci…c kinds of attitudes in question and describes the properties of a large class of aggregation rules applicable to a variety of belief-like attitudes. Our approach integrates some previously disconnected areas of investigation. (shrink)

Does the desirability of a proposition depend on whether it is true? Not according to the Invariance assumption, held by several notable philosophers. The Invariance assumption plays an important role in David Lewis’ famous arguments against the so-called Desire-as-Belief thesis (DAB), an anti-Humean thesis according to which a rational agent desires a proposition exactly to the degree that she believes the proposition to be desirable. But the assumption is of interest independently of Lewis’ arguments, for instance since both Richard Jeffrey (...) and James Joyce make the assumption (or, strictly speaking, accept a thesis that implies Invariance) in their influential books on decision theory. The main claim to be defended in this paper is that Invariance is incompatible with certain assumptions of decision theory. I show that the assumption fails on the most common interpretations of desirability and/or choice-worthiness found in decision theory. I moreover show that Invariance is inconsistent with Richard Jeffrey’s decision theory, on which Lewis’ arguments against DAB are based. Finally, I show that Invariance contradicts how we in general do and should think about conditional desirability. (shrink)

This paper has three interdependent aims. The first is to make Reichenbach’s views on induction and probabilities clearer, especially as they pertain to his pragmatic justification of induction. The second aim is to show how his view of pragmatic justification arises out of his commitment to extensional empiricism and moots the possibility of a non-pragmatic justification of induction. Finally, and most importantly, a formal decision-theoretic account of Reichenbach’s pragmatic justification is offered in terms both of the minimax principle and the (...) dominance principle. (shrink)

Abstract:I address an overlooked question about the structure of the cognitive/conative model of the mind that underlies much of the work in economics, psychology and philosophy: namely, whether conative states are fundamentally monistic (desire-like) or comparative (preference-like). I argue that two seemingly promising sets of theoretical considerations – namely, the structure of Rational Choice Theory, and considerations of computational efficiency – are unable to resolve this debate. Given this, I suggest that a consideration that speaks in favour of the preference-based (...) view is the fact that it makes it easier to explain certain empirically observed patterns in decision making. (shrink)

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.

It has been argued by several philosophers that a morally motivated rational agent who has to make decisions under conditions of moral uncertainty ought to maximize expected moral value in his choices, where the expectation is calculated relative to the agent's moral uncertainty. I present a counter-example to this thesis and to a larger family of decision rules for choice under conditions of moral uncertainty. Based on this counter-example, I argue against the thesis and suggest a reason for its failure (...) – that it is based on the false assumption that inter-theoretical comparisons of moral value are meaningful. (shrink)

This paper aims to draw attention to an important but underappreciated aspect of the instrumental value of freedom: its diagnostic value. This is the value freedom has insofar as it makes it possible for us to discover ourselves and improve ourselves in our capacity to make value judgements. Diagnostic value, I argue, has an important role to play in explaining the value we attach to freedom. Accordingly, this paper is aimed at elucidating this concept, examining its relevance to our lives, (...) and defending an account of how to measure the diagnostic value of opportunities and sets of opportunities. (shrink)

This paper presents some impossibility results for certain views about what you should do when you are uncertain about which moral theory is true. I show that under reasonable and extremely minimal ways of defining what a moral theory is, it follows that the concept of expected moral choiceworthiness is undefined, and more generally that any theory of decision-making under moral uncertainty must generate pathological results.

The Desire-as-Belief thesis (DAB) states that any rational person desires a proposition exactly to the degree that she believes or expects the proposition to be good. Many people take David Lewis to have shown the thesis to be inconsistent with Bayesian decision theory. However, as we show, Lewis's argument was based on an Invariance condition that itself is inconsistent with the (standard formulation of the) version of Bayesian decision theory that he assumed in his arguments against DAB. The aim of (...) this paper is to explore what impact the rejection of Invariance has on the DAB thesis. Without assuming Invariance, we first refute all versions of DAB that entail that there are only two levels of goodness. We next consider two theses according to which rational desires are intimately connected to expectations of (multi-levelled) goodness, and show that these are consistent with Bayesian decision theory as long as we assume that the contents of 'value propositions' are not fixed. We explain why this conclusion is independently plausible, and show how to construct such propositions. (shrink)

According to the traditional view, beliefs and desires are mental representations that play particular functional roles. A belief that P is state which represents P and plays the belief-role, while a desire that P is a state which represents that P and plays the desire-role. In this dissertation I argue that the traditional view has trouble accounting for (a) role that belief and desire play in the causal and rational explanation of behaviour and (b) our knowledge of our own conscious, (...) occurrent beliefs and desires. -/- In its place I argue for Pure Attitude Representationalism (PAR), which holds that beliefs and desires are not to be distinguished from one another by their functional role, but instead entirely by their representational content. According to PAR, desires are distinct from beliefs not because they do different things, but because desires represent things as being rewarding. Throughout the three papers that comprise this dissertation I argue that PAR provides a better explanation of (a) and (b). (shrink)

This thesis concerns the measurement of freedom, and its value. Specifically, I am concerned with three overarching questions. First, can we measure the extent of an individual’s freedom? It had better be that we can, otherwise much ordinary and intuitive talk that we would like to vindicate – say, about free persons being freer than slaves – will turn out to be false or meaningless. Second, in what ways is freedom valuable, and how is this value measured? It matters, for (...) example, whether freedom is valuable only insofar as it enables us to pursue specific ends we happen to value for independent reasons, or whether it is also valuable in itself. In the latter case, but not the former, more freedom will always be better. Likewise, it’s important to get clarity on what ends, exactly, freedom is especially instrumentally valuable in promoting, since this goes to how much we should care about it. And finally, the liberal political tradition asserts that there is a special sphere of personal choices within which individuals should be free to do as they please, for reasons over and above the value of freedom itself. Now, can we measure the extent to which states and individuals respect individual liberties, and can we weigh the importance of respecting liberty against competing values like social welfare? To answer these questions, I follow the axiomatic tradition of social choice theory, and I develop several novel measures of freedom – including the first measure of freedom ever proposed that is sensitive to how modally robustly our options are available – a novel approach to measuring the diversity of an opportunity set, and I develop an account of the value of freedom according to which an important part of why freedom matters is that it enables us to improve our preferences through learning, and I construct ways of measuring the value of freedom along this dimension of value. Finally, in later chapters, I provide a representation result for a measure of illiberalism, i.e. of the degree to which states fail to respect the rights of their citizens, and I extend this result to provide a characterization of moral theories that express concern for respecting the rights of others. The final chapter closes by discussing how this concern may be weighed against concerns for social welfare. (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.

How can the propositional attitudes of several individuals be aggregated into overall collective propositional attitudes? Although there are large bodies of work on the aggregation of various special kinds of propositional attitudes, such as preferences, judgments, probabilities and utilities, the aggregation of propositional attitudes is seldom studied in full generality. In this paper, we seek to contribute to filling this gap in the literature. We sketch the ingredients of a general theory of propositional attitude aggregation and prove two new theorems. (...) Our first theorem simultaneously characterizes some prominent aggregation rules in the cases of probability, judgment and preference aggregation, including linear opinion pooling and Arrovian dictatorships. Our second theorem abstracts even further from the specific kinds of attitudes in question and describes the properties of a large class of aggregation rules applicable to a variety of belief-like attitudes. Our approach integrates some previously disconnected areas of investigation. (shrink)