Several philosophers deny that an individual person’s emissions of greenhouse gas do any harm; I call these “individual denialists.” I argue that each individual’s emissions may do harm, and that they certainly do expected harm. I respond to the denialists’ arguments.

A survey of various candidates shows that there is no defensible moral principle that shows that individuals have an obligation to reduce their greenhouse gas emissions.

Our thesis is that there is no moral requirement to refrain from emitting reasonable amounts of greenhouse gases solely in order to enjoy oneself. Joyriding in a gas guzzler provides our paradigm example. We first distinguish this claim that there is no moral requirement to refrain from joyguzzling from other more radical claims. We then review several different proposed objections to our view. These include: the claim that joyguzzling exemplifies a vice, causes or contributes to harm, has negative expected value, (...) exceeds our fair share of global emissions, and undermines political duties. We show why none of these objections succeeds and conclude that no good reason has yet been proposed that shows why joyguzzling violates a moral requirement. (shrink)

The lesson to be learned from the paradoxical St. Petersburg game and Pascal’s Mugging is that there are situations where expected utility maximizers will needlessly end up poor and on death’s door, and hence we should not be expected utility maximizers. Instead, when it comes to decision-making, for possibilities that have very small probabilities of occurring, we should discount those probabilities down to zero, regardless of the utilities associated with those possibilities.

Several philosophers claim that the greenhouse gas emissions from actions like a Sunday drive are so miniscule that they will make no difference whatsoever with regard to anthropogenic global climate change (AGCC) and its expected harms. This paper argues that this claim of individual causal inefficacy is false. First, if AGCC is not reducible at least in part to ordinary actions, then the cause would have to be a metaphysically odd emergent entity. Second, a plausible (dis-)utility calculation reveals that such (...) actions have a not-insignificant amount of expected harm. One upshot is that the near-exclusive focus in the literature on AGCC as a collective action problem is too restricted. The paper also provides several moral psychological explanations of why it is so difficult to comprehend individual responsibility with regard to global phenomena, including a reappraisal of Thomas Nagel’s view of the absurd. (shrink)

In a well-known paper, Nick Bostrom presents a confrontation between a fictionalised Blaise Pascal and a mysterious mugger. The mugger persuades Pascal to hand over his wallet by exploiting Pascal's commitment to expected utility maximisation. He does so by offering Pascal an astronomically high reward such that, despite Pascal's low credence in the mugger's truthfulness, the expected utility of accepting the mugging is higher than rejecting it. In this article, I present another sort of high value, low credence mugging. This (...) time, the mugger utilises research on existential risk and the long-term potential of humanity to exploit Pascal's expected-utility-maximising descendant. This mugging is more insidious than Bostrom's original as it relies on plausible facts about the long-term future, as well as realistic credences about how our everyday actions could, albeit with infinitesimally low likelihood, affect the future of humanity. (shrink)

There is a well-known moral quandary concerning how to account for the rightness or wrongness of acts that clearly contribute to some morally significant outcome – but which each seem too small, individually, to make any meaningful difference. One consequentialist-friendly response to this problem is to deny that there could ever be a case of this type. This paper pursues this general strategy, but in an unusual way. Existing arguments for the consequentialist-friendly position are sorites-style arguments. Such arguments imagine varying (...) a subject’s predicament bit by bit until it is clear that a relevant difference has been achieved. The arguments offered in this paper are structurally different, and do not rely on any sorites series. For this reason, they are not vulnerable to objections that have been leveled against the sorites-style arguments. (shrink)

The problem of the man who met death in Damascus appeared in the infancy of the theory of rational choice known as causal decision theory. A straightforward, unadorned version of causal decision theory is presented here and applied, along with Brian Skyrms’ deliberation dynamics, to Death in Damascus and similar problems. Decision instability is a fascinating topic, but not a source of difficulty for causal decision theory. Andy Egan’s purported counterexample to causal decision theory, Murder Lesion, is considered; a simple (...) response shows how Murder Lesion and similar examples fail to be counterexamples, and clarifies the use of the unadorned theory in problems of decision instability. I compare unadorned causal decision theory to previous treatments by Frank Arntzenius and by Jim Joyce, and recommend a well-founded heuristic that all three accounts can endorse. Whatever course deliberation takes, causal decision theory is consistently a good guide to rational action. (shrink)

The following values have no corresponding Zotero field: PB - JSTOR.

This paper presents a new solution to the problems for orthodox decision theory posed by the Pasadena game and its relatives. I argue that a key question raised by consideration of these gambles is whether evaluative compositionality (as I term it) is a requirement of rationality: is the value that an ideally rational agent places on a gamble determined by the values that she places on its possible outcomes, together with their mode of composition into the gamble (i.e. the probabilities (...) assigned to them)? The paper first outlines a certain simple response to the Pasadena game and identifies two problems with this response, the second of which is that it leads to a wholesale violation of evaluative compositionality. I then argue that rationality does not require decision makers to factor in outcomes of arbitrarily low probability. A method for making decisions which flows from this basic idea is then developed, and it is shown that this decision method (Truncation) leads to a limited — as opposed to wholesale — violation of evaluative compositionality. The paper then argues that the truncation method yields solutions to the problems posed by the Pasadena game and its relatives that are both attractive in themselves and superior to those yielded by alternative proposals in the literature. (shrink)

In some dark alley. . . Mugger: Hey, give me your wallet. Pascal: Why on Earth would I want to do that? Mugger: Otherwise I’ll shoot you. Pascal: But you don’t have a gun. Mugger: Oops! I knew I had forgotten something. Pascal: No wallet for you then. Have a nice evening. Mugger: Wait! Pascal: Sigh. Mugger: I’ve got a business proposition for you. . . . How about you give me your wallet now? In return, I promise to come (...) to your house tomorrow and give you double the value of what’s in the wallet. Not bad, eh? A 200% return on investment in 24 hours. (shrink)

Nebel argues for the Repugnant Conclusion via the “Intrapersonal Repugnant Conclusion,” on which certainty of a mediocre life is better for individuals than a sufficiently small chance of an excellent life. In this article, I deny that acceptance of the Intrapersonal Repugnant Conclusion leads us to the Repugnant Conclusion. I point out that on many views which avoid the Repugnant Conclusion we should discount very small probabilities down to zero. If we do, then Nebel’s crucial premise of Ex Ante Pareto (...) fails, because discounting at the individual level can fail to match up with discounting at the population level. (shrink)

A decade ago, Harris Nover and I introduced the Pasadena game, which we argued gives rise to a new paradox in decision theory even more troubling than the St Petersburg paradox. Gwiazda's and Smith's articles in this volume both offer revisionist solutions. I critically engage with both articles. They invite reflections on a number of deep issues in the foundations of decision theory, which I hope to bring out. These issues include: some ways in which orthodox decision theory might be (...) supplemented; the role of simulations of such infinite games; the role of small probabilities, and of idealization, in decision theory; tolerance about practical norms; and alternative ways of understanding decision theory's job description. (shrink)

In response to Smith, I argue that probabilities cannot be rationally neglected. I show that Smith’s proposal for ignoring low-probability outcomes must, on pain of violating dominance reasoning, license taking arbitrarily high risk for arbitrarily little reward.

A 1% skeptic is someone who has about a 99% credence in non-skeptical realism and about a 1% credence in the disjunction of all radically skeptical scenarios combined. The first half of this essay defends the epistemic rationality of 1% skepticism, appealing to dream skepticism, simulation skepticism, cosmological skepticism, and wildcard skepticism. The second half of the essay explores the practical behavioral consequences of 1% skepticism, arguing that 1% skepticism need not be behaviorally inert.

A 1% skeptic is someone who has about a 99% credence in non-skeptical realism and about a 1% credence that some radically skeptical scenario obtains. The first half of this essay defends the epistemic rationality of 1% skepticism, endorsing modest versions of dream skepticism, simulation skepticism, cosmological skepticism, and wildcard skepticism. The second half of the essay explores the practical behavioral consequences of 1% skepticism.

This paper revisits the Pasadena game (Nover and Háyek 2004), a St Petersburg-like game whose expectation is undefined. We discuss serveral respects in which the Pasadena game is even more troublesome for decision theory than the St Petersburg game. Colyvan (2006) argues that the decision problem of whether or not to play the Pasadena game is ‘ill-posed’. He goes on to advocate a ‘pluralism’ regarding decision rules, which embraces dominance reasoning as well as maximizing expected utility. We rebut Colyvan’s argument, (...) offering several considerations in favour of the Pasadena decision problem being well posed. To be sure, current decision theory, which is underpinned by various preference axioms, leaves indeterminate how one should value the Pasadena game. But we suggest that determinacy might be achieved by adding further preference axioms. We conclude by opening the door to a far greater plurality of decision rules. We suggest how the goal of unifying these rules might guide future research. (shrink)

A. Pascal's statement of his wager argument is couched in terms of the theory of probability and the theory of games, and the exposition is unclear and unnecessarily complicated. The following is a ‘creative’ reformulation of the argument designed to avoid some of the objections which have been or might be raised against the original.

A. Pascal's statement of his wager argument is couched in terms of the theory of probability and the theory of games, and the exposition is unclear and unnecessarily complicated. The following is a ‘creative’ reformulation of the argument designed to avoid some of the objections which have been or might be raised against the original.