What is the prudentially right thing to do in situations in which our actions will shape our preferences? Suppose, for instance, that you are considering getting married, and that you know that if you get married, you will prefer being unmarried, and that if you stay unmarried, you will prefer being married. This is the problem I will deal with in this article. I will begin by explaining why preferences matter to prudence. I will then go on to discuss a (...) couple of unsuccessful theories and see what we can learn from their mistakes. One of the most important lessons is that how you would have felt about a life had you never led it is irrelevant to the question of what you prudentially ought to do. My theory takes this into account. What counts is how you feel about a life when you are actually leading it. (Published Online August 21 2006). (shrink)

It is a platitude among decision theorists that agents should choose their actions so as to maximize expected value. But exactly how to define expected value is contentious. Evidential decision theory (henceforth EDT), causal decision theory (henceforth CDT), and a theory proposed by Ralph Wedgwood that this essay will call benchmark theory (BT) all advise agents to maximize different types of expected value. Consequently, their verdicts sometimes conflict. In certain famous cases of conflict—medical Newcomb problems—CDT and BT seem to get (...) things right, while EDT seems to get things wrong. In other cases of conflict, including some recent examples suggested by Andy Egan, EDT and BT seem to get things right, while CDT seems to get things wrong. In still other cases, EDT and CDT seems to get things right, while BT gets things wrong. It's no accident, this essay claims, that all three decision theories are subject to counterexamples. Decision rules can be reinterpreted as voting rules, where the voters are the agent's possible future selves. The problematic examples have the structure of voting paradoxes. Just as voting paradoxes show that no voting rule can do everything we want, decision-theoretic paradoxes show that no decision rule can do everything we want. Luckily, the so-called “tickle defense” establishes that EDT, CDT, and BT will do everything we want in a wide range of situations. Most decision situations, this essay argues, are analogues of voting situations in which the voters unanimously adopt the same set of preferences. In such situations, all plausible voting rules and all plausible decision rules agree. (shrink)

Benchmark theory , introduced by Ralph Wedgwood, departs from decision theories of pure expectation maximization like evidential decision theory and causal decision theory and instead ranks actions according to the desirability of an outcome they produce in some state of affairs compared to a standard—a benchmark—for that state of affairs. Wedgwood motivates BT through what he terms Gandalf’s principle, that the merits of an action in a given state should be evaluated relative only to the performances of other actions in (...) that state, and not to their performances in other states. Although BT succeeds in selecting intuitively rational actions in a number of cases—including some in which EDT or CDT seem to go wrong—it places constraints on rational decision-making that either lack motivation or are untenable. Specifically, I argue that as it stands BT is committed both to endorsing and rejecting the independence of irrelevant alternatives. Furthermore its requirement that weakly dominated actions be excluded from consideration of rational action lacks motivation and threatens to collide with traditional game theory. In the final section of the paper, I construct a counterexample to BT. (shrink)

An action is unratifiable when, on the assumption that one performs it, another option has higher expected utility. Unratifiable actions are often claimed to be somehow rationally defective. But in some cases where multiple options are unratifiable, one unratifiable option can still seem preferable to another. We should respond, I argue, by invoking a graded notion of ratifiability.

I argue that standard decision theories, namely causal decision theory and evidential decision theory, both are unsatisfactory. I devise a new decision theory, from which, under certain conditions, standard game theory can be derived.

You should rather play hide-and-seek against someone who cannot predict where you hide than against someone who can, as the article illustrates in connection with a high-stakes example. Causal Decision Theory denies this. So Causal Decision Theory is false.

Kolmogorov''s axiomatization of probability includes the familiarratio formula for conditional probability: 0).$$ " align="middle" border="0">.

This article proposes a new theory of rational decision, distinct from both causal decision theory (CDT) and evidential decision theory (EDT). First, some intuitive counterexamples to CDT and EDT are presented. Then the motivation for the new theory is given: the correct theory of rational decision will resemble CDT in that it will not be sensitive to any comparisons of absolute levels of value across different states of nature, but only to comparisons of the differences in value between the available (...) options within states of nature; however, the correct theory will also resemble EDT in that it will rely on conditional probabilities (not unconditional probabilities). The new theory gives a prominent role to the notion of a “benchmark” for each state of nature, by comparison with which the value of the available options in that state of nature are measured, and so it has been called the Benchmark Theory (BT). It is argued that BT gives the right verdict on the cases that seem to be counterexamples to CDT and EDT. Finally, some objections to BT are considered and answered. (shrink)

Suppose that we want to frame a conception of reasons that isn't relativized to the inclinations of particular agents. That is, we want to identify particular things that count as reasons for acting simpliciter and not merely as reasons for some agents rather than others, depending on their inclinations. One way to frame such a conception is to name some features that an action can have and to say that they count as reasons for someone whether or not he is (...) inclined to care about them. The problem with the resulting conception, as we have seen, is that it entails the normative judgment that one ought to be inclined to care about the specified features, on pain of irrationality, and this normative judgment requires justification. The advantage of internalism is that it avoids these normative commitments. It says that things count as reasons for someone only if he is inclined to care about them, and so it leaves the normative question of whether to care about them entirely open. Yet if we try to leave this question open, by defining things as reasons only for those inclined to care about them, we'll end up with a definition that's relativized to the inclinations of particular agents—won't we? Not necessarily. For suppose that all reasons for acting are features of a single kind, whose influence depends on a single inclination. And suppose that the inclination on which the influence of reasons depends is, not an inclination that distinguishes some agents from others, but rather an inclination that distinguishes agents from nonagents. In that case, to say that these features count as reasons only for those who are inclined to care about them will be to say that they count as reasons only for agents—which will be to say no less than that they are reasons for acting, period, since applying only to agents is already part of the concept of reasons for acting. The restriction on the application of reasons will drop away from our definition, since it restricts their application, not to some proper subset of agents, but rather to the set of all agents, which is simply the universe of application for reasons to act. (shrink)

It is a popular view thatpractical deliberation excludes foreknowledge of one's choice. Wolfgang Spohn and Isaac Levi have argued that not even a purely probabilistic self-predictionis available to thedeliberator, if one takes subjective probabilities to be conceptually linked to betting rates. It makes no sense to have a betting rate for an option, for one's willingness to bet on the option depends on the net gain from the bet, in combination with the option's antecedent utility, rather than on the offered (...) odds. And even apart from this consideration, assigning probabilities to the options among which one is choosing is futile since such probabilities could be of no possible use in choice. The paper subjects these arguments to critical examination and suggests that, appearances notwithstanding, practical deliberation need not crowd outself-prediction. (shrink)

Probabilistic accounts of causality have long had trouble with ‘spurious’ evidential correlations. Such correlations are also central to the case for causal decision theory—the argument that evidential decision theory is inadequate to cope with certain sorts of decision problem. However, there are now several strong defences of the evidential theory. Here I present what I regard as the best defence, and apply it to the probabilistic approach to causality. I argue that provided a probabilistic theory appeals to the notions of (...) agency and effective strategy, it can avoid the problem of spurious causes. I show that such an appeal has other advantages; and argue that it is not illegitimate, even for a causal realist. (shrink)

This paper considers the question of whether predictions of wrongdoing are relevant to our moral obligations. After giving an analysis of ‘won’t’ claims (i.e., claims that an agent won’t Φ), the question is separated into two different issues: firstly, whether predictions of wrongdoing affect our objective moral obligations, and secondly, whether self-prediction of wrongdoing can be legitimately used in moral deliberation. I argue for an affirmative answer to both questions, although there are conditions that must be met for self-prediction to (...) be appropriate in deliberation. The discussion illuminates an interesting and significant tension between agency and prediction. (shrink)

This paper considers the question of whether predictions of wrongdoing are relevant to our moral obligations. After giving an analysis of 'won't' claims, the question is separated into two different issues: firstly, whether predictions of wrongdoing affect our objective moral obligations, and secondly, whether self-prediction of wrongdoing can be legitimately used in moral deliberation. I argue for an affirmative answer to both questions, although there are conditions that must be met for self-prediction to be appropriate in deliberation. The discussion illuminates (...) an interesting and significant tension between agency and prediction. (shrink)

It is a popular view thatpractical deliberation excludes foreknowledge of one's choice. Wolfgang Spohn and Isaac Levi have argued that not even a purely probabilistic self-predictionis available to thedeliberator, if one takes subjective probabilities to be conceptually linked to betting rates. It makes no sense to have a betting rate for an option, for one's willingness to bet on the option depends on the net gain from the bet, in combination with the option's antecedent utility, rather than on the offered (...) odds. And even apart from this consideration, assigning probabilities to the options among which one is choosing is futile since such probabilities could be of no possible use in choice. The paper subjects these arguments to critical examination and suggests that, appearances notwithstanding, practical deliberation need not crowd outself-prediction. (shrink)

Newcomb's problem and similar cases show the need to incorporate causal distinctions into the theory of rational decision; the usual noncausal decision theory, though simpler, does not always give the right answers. I give my own version of causal decision theory, compare it with versions offered by several other authors, and suggest that the versions have more in common than meets the eye.

Andy Egan has recently produced a set of alleged counterexamples to causal decision theory in which agents are forced to decide among causally unratifiable options, thereby making choices they know they will regret. I show that, far from being counterexamples, CDT gets Egan's cases exactly right. Egan thinks otherwise because he has misapplied CDT by requiring agents to make binding choices before they have processed all available information about the causal consequences of their acts. I elucidate CDT in a way (...) that makes it clear where Egan goes wrong, and which explains why his examples pose no threat to the theory. My approach has similarities to a modification of CDT proposed by Frank Arntzenius, but it differs in the significance that it assigns to potential regrets. I maintain, contrary to Arntzenius, that an agent facing Egan's decisions can rationally choose actions that she knows she will later regret. All rationality demands of agents it that they maximize unconditional causal expected utility from an epistemic perspective that accurately reflects all the available evidence about what their acts are likely to cause. This yields correct answers even in outlandish cases in which one is sure to regret whatever one does. (shrink)

Isaac Levi has long criticized causal decisiontheory on the grounds that it requiresdeliberating agents to make predictions abouttheir own actions. A rational agent cannot, heclaims, see herself as free to choose an actwhile simultaneously making a prediction abouther likelihood of performing it. Levi is wrongon both points. First, nothing in causaldecision theory forces agents to makepredictions about their own acts. Second,Levi's arguments for the ``deliberation crowdsout prediction thesis'' rely on a flawed modelof the measurement of belief. Moreover, theability of agents (...) to adopt beliefs about theirown acts during deliberation is essentialto any plausible account of human agency andfreedom. Though these beliefs play no part inthe rationalization of actions, they arerequired to account for the causalgenesis of behavior. To explain the causes ofactions we must recognize that (a) an agentcannot see herself as entirely free in thematter of A unless she believes herdecision to perform A will cause A,and (b) she cannot come to a deliberatedecision about A unless she adoptsbeliefs about her decisions. FollowingElizabeth Anscombe and David Velleman, I arguethat an agent's beliefs about her own decisionsare self-fulfilling, and that this can beused to explain away the seeming paradoxicalfeatures of act probabilities. (shrink)

According to the so-called ‘deliberation crowds out prediction’ thesis, while deliberating about what you’ll do, you cannot rationally have credences for what you’ll do – you cannot rationally have option-credences. Versions of the thesis have been defended by authors such as Spohn, Levi, Gilboa, Price, Louise, and others. After registering a number of concerns about the thesis, I rehearse and rebut many of the main arguments for it, grouped according to their main themes: agency, vacuity, betting, and decision-theoretical considerations. I (...) go on to suggest many possible theoretical roles for option-credences. -/- I locate the debate about the thesis in a broader discussion: Are there rational credence gaps – propositions to which one cannot rationally assign credences? If there are, they spell trouble for various foundations of Bayesian epistemology, including the usual ratio formula for conditional probability, conditionalization, decision theory, and independence. According to the thesis, credence gaps are completely mundane; they arise every time someone rationally deliberates. But these foundations are safe from any threat here, I contend, since the thesis is false. Deliberation welcomes prediction. (shrink)

Many philosophers (myself included) have been converted to causal decision theory by something like the following line of argument: Evidential decision theory endorses irrational courses of action in a range of examples, and endorses “an irrational policy of managing the news”. These are fatal problems for evidential decision theory. Causal decision theory delivers the right results in the troublesome examples, and does not endorse this kind of irrational news-managing. So we should give up evidential decision theory, and be causal decision (...) theorists instead. Unfortunately, causal decision theory has its own family of problematic examples for which it endorses irrational courses of action, and its own irrational policy that it is committed to endorsing. These are, I think, fatal problems for causal decision theory. I wish that I had another theory to offer in its place. (shrink)

In Intricate Ethics, Kamm questions the moral importance of some non-consequentialist distinctions and then introduces and argues for the moral importance of ...

In a famous paper in Noûs in 1979, John Perry points out that action depends on indexical beliefs. In addition to “third-person” information about her environment, an agent need “first-person” information about where, when and who she is. This conclusion is widely interpreted as a reason for thinking that tensed claims cannot be translated without loss into untensed language; but not as a reason for realism about tensed facts. In another famous paper in the same volume of Noûs, Nancy Cartwright (...) argues that action requires that agents represent their world in causal terms, rather than merely probabilistic terms: for, Cartwright argues, there’s a distinction between effective and ineffective strategies, that otherwise goes missing. This is widely taken as a reason for thinking that causal claims cannot be translated without loss into merely probabilistic claims; and also – in contrast to Perry’s case – widely regarded as a reason for realism about causation. In this paper I ask whether the latter conclusion is compulsory, or whether, as in Perry’s case, the need for causal beliefs might merely reflect some “situated” aspect of a decision-maker’s perspective. (shrink)