It is often thought that the main significant difference between evidential decision theory and causal decision theory is that they recommend different acts in Newcomb-style examples (broadly construed) where acts and states are correlated in peculiar ways. However, this paper presents a class of non-Newcombian examples that evidential decision theory cannot adequately model whereas causal decision theory can. Briefly, the examples involve situations where it is clearly best to perform an act that will not influence the desired outcome. On evidential (...) decision theory—but not causal decision theory—this situation turns out to be impossible: acts that an agent does not think influence the desired outcome are never optimal. Typically, sophisticated versions of evidential decision theory emulate causal decision theoretic reasoning by (implicitly) conditioning on causal confounders, but in the kind of example considered here, this trick does not work. The upshot is that there is more to causal reasoning than has so far been appreciated. (shrink)

According to the received view in metaethics, a Neo-Humean theory of rationality entails that there cannot be any objective moral reasons, i.e. moral reasons that are independent of actual desires. In this paper, I argue that there is a version of this theory that is compatible with the existence of objective moral reasons. The key is to distinguish between (i) the process of rational deliberation that starts off in an agent's actual desires, and (ii) the rational principle that an agent (...) employs in such a process. I maintain that it is the latter which explains why it is rational for an agent to have a certain desire, not the former. As a result, there might be two types of principles. The second type of principle leaves room for objective moral reasons. (shrink)

The crucial premise of the standard argument for two-boxing in Newcomb's problem, a causal dominance principle, is false. We present some counterexamples. We then offer a metaethical explanation for why the counterexamples arise. Our explanation reveals a new and superior argument for two-boxing, one that eschews the causal dominance principle in favor of a principle linking rational choice to guidance and actual value maximization.

In “A Subjectivist’s Guide to Objective Chance,” David Lewis says that he is “led to wonder whether anyone but a subjectivist is in a position to understand objective chance.” The present essay aims to motivate this same Lewisean attitude, and a similar degree of modest subjectivism, with respect to objective causation. The essay begins with Newcomb problems, which turn on an apparent tension between two principles of choice: roughly, a principle sensitive to the causal features of the relevant situation, and (...) a principle sensitive only to evidential factors. Two-boxers give priority to causal beliefs, and one-boxers to evidential beliefs. The essay notes that a similar issue can arise when the modality in question is chance, rather than causation. In this case, the conflict is between decision rules based on credences guided solely by chances, and rules based on credences guided by other sorts of probabilistic evidence. Far from excluding cases of the latter kind, Lewis’s Principal Principle explicitly allows for them, in the form of the caveat that credences should follow beliefs about chances only in the absence of “inadmissible evidence.” The essay then exhibits a tension in Lewis’s views on these two matters, by presenting a class of decision problems—some of them themselves Newcomb problems—in which Lewis’s view of the relevance of inadmissible evidence seems in tension with his causal decision theory. It offers a diagnosis for this dilemma and proposes a remedy, based on an extension of a proposal due to Ned Hall and others from the case of chance to that of causation. The remedy suggests a new view of the relation between causal decision theory and evidential decision theory, namely, that they stand to each other much as chance stands to credence, being objective and subjective faces of the same practical coin. This has much the same metaphysical benefits as Lewis’s own view of chance and also throws interesting new light on Newcomb problems, providing an irenic resolution of the apparent disagreement between causal and evidential decision rules. (shrink)

The dispute in philosophical decision theory between causalists and evidentialists remains unsettled. Many are attracted to the causal view’s endorsement of a species of dominance reasoning, and to the intuitive verdicts it gets on a range of cases with the structure of the infamous Newcomb’s Problem. But it also faces a rising wave of purported counterexamples and theoretical challenges. In this paper I will describe a novel decision theory which saves what is appealing about the causal view while avoiding its (...) most worrying objections, and which promises to generalize to solve a set of related problems in other normative domains. (shrink)

It is commonly assumed that preferences are determinate; that is, that an agent who has a preference knows that she has the preference in question and is disposed to act upon it. This paper argues the dubiousness of that assumption. An account of indeterminate preferences in terms of self-predicting subjective probabilities is given, and a decision rule for choices involving indeterminate preferences is proposed. Wolfgang Spohn’s and Isaac Levi ’s arguments against self-predicting probabilities are also considered, in light of Wlodek (...) Rabinowicz’s recent criticism. (shrink)

According to classical decision theory, an agent realises at time t the option with maximum expected utility (determined by his beliefs and desires at t), where the relevant options are possible actions performed at t. I consider an alternative according to which the relevant options are in general plans, complex courses of action extending into the future.

According to some, taking moral testimony is a potentially decent way to exercise one's moral agency. According to others, it amounts to a failure to live up to minimal standards of moral worth. What's the issue? Is it conceptual or empirical? Is it epistemological or moral? Is there a ‘puzzle’ of moral testimony; or are there many, or none? I argue that there is no distinctive puzzle of moral testimony. The question of its legitimacy is as much a moral or (...) political as an epistemological question. Its answer is as much a matter of contingent empirical fact as a matter of a priori necessity. In the background is a mixture of normative and descriptive issues, including the value of autonomy, the nature of legitimate authority, and who to trust. (shrink)

One can interpret the No Probabilities for Acts-Principle, namely that any adequate quantitative decision model must in no way contain subjective probabilities for actions in two ways: it can either refer to actions that are performable now and extend into the future or it can refer to actions that are not performable now, but will be in the future. In this paper, I will show that the former is the better interpretation of the principle.

What should we do when we won't do as we ought? Suppose it ought to be that the procrastinating professor accept the task of reviewing a book, and actually review the book. It seems clear that given he won't review it, he ought not to accept the task. That is a genuine moral obligation in light of less than perfect circumstances. I want to entertain the possibility that a set of such obligations form something like a 'practical morality'; that which (...) we ought to do given that we're unlikely or unwilling to do much of what ideal morality demands. If it is possible to give a coherent account of these kinds of obligations, then it is possible to entertain the idea that these obligations are in fact what morality demands. The conceptual truths about justice (good, right, fairness) that come from ideals are one thing; the actions that morality demands of people given their actual circumstances are quite another. In this paper I will ask about the kinds of facts that can be used to establish a more circumscribed set of obligations than we get from the orthodox view about moral obligation. (shrink)

In this paper I study dynamical models of rational deliberation within the context of Newcomb's problem. Such models have been used to argue against the soundness of the "tickle'" defense of evidential decision theory, which is based on the idea that sophisticated decision makers can break correlations between states and acts by introspecting their own beliefs and desires. If correct, this would show that evidential decision theory agrees with the recommendations of causal decision theory. I argue that an adequate understanding (...) of rational deliberation leads to deliberative processes for which this idea works. My proposal is modest, though. Evidential decision theory cannot always be reconciled with causal decision theory along the lines suggested here, but the agreement between the two theories is broader than previously thought. (shrink)

Decision-theoretic representation theorems have been developed and appealed to in the service of two important philosophical projects: in attempts to characterise credences in terms of preferences, and in arguments for probabilism. Theorems developed within the formal framework that Savage developed have played an especially prominent role here. I argue that the use of these ‘Savagean’ theorems create significant difficulties for both projects, but particularly the latter. The origin of the problem directly relates to the question of whether we can have (...) credences regarding acts currently under consideration and the consequences which depend on those acts; I argue that such credences are possible. Furthermore, I argue that attempts to use Jeffrey’s non-Savagean theorem in the service of these two projects may not fare much better. (shrink)

This paper aims to make three contributions to decision theory. First there is the hope that it will help to re-establish the legitimacy of the problem, pace various recent analyses provided by Maitzen and Wilson, Slezak and Priest. Second, after pointing out that analyses of the problem have generally relied upon evidence that is conditional on the taking of one particular option, this paper argues that certain assumptions implicit in those analyses are subtly flawed. As a third contribution, the piece (...) aims to draw attention to an important similarity between Newcomb’s problem and the toxin puzzle. In short, both problems illustrate the fact that you can have a reason to intend to φ without having a reason to actually φ. (shrink)

This paper argues that, with certain provisos, predicting one's future actions is incompatible with rationally deliberating about whether to perform those actions. It follows that fully rational omniscient agents are impossible, since an omniscient being could never rationally deliberate about what to do. Consequently, theories that explain practical reasons in terms of the choices of a perfectly rational omniscient agent must fail. The paper considers several ways of defending the possibility of an omniscient agent, and concludes that while some of (...) these may work, they are inconsistent with the aim of explaining practical normativity by appeal to such an agent. (shrink)