Solving a Paradox of Evidential Equivalence

David Builes presents a paradox concerning how confident you should be that any given member of an infinite collection of fair coins landed heads, conditional on the information that they were all flipped and only finitely many of them landed heads. We argue that if you should have any conditional credence at all, it should be 1/2

Solving a paradox of evidential equivalence

David Builes presents a paradox concerning how confident you should be that any given member of an infinite collection of fair coins landed heads, conditional on the information that they were all flipped and only finitely many of them landed heads. We argue that if you should have any conditional credence at all, it should be 1/2

Updating Without Evidence

Sometimes you are unreliable at fulfilling your doxastic plans: for example, if you plan to be fully confident in all truths, probably you will end up being fully confident in some falsehoods by mistake. In some cases, there is information that plays the classical role of *evidence*—your beliefs are perfectly discriminating with respect to some possible facts about the world—and there is a standard expected-accuracy-based justification for planning to *conditionalize* on this evidence. This planning-oriented justification extends to some cases where you do not have transparent evidence, in the sense that your beliefs are not perfectly discriminating with respect to any non-trivial facts. In other cases, accuracy considerations do not tell you to plan to conditionalize on any information at all, but rather to plan to follow a different updating rule. Even in the absence of evidence, accuracy considerations can guide your doxastic plan

Multiple Universes and Self-Locating Evidence

Is the fact that our universe contains fine-tuned life evidence that we live in a multiverse? Hacking (1987) and White (2000) influentially argue that it is not. We approach this question through a systematic framework for self-locating epistemology. As it turns out, leading approaches to self-locating evidence agree that the fact that our own universe contains fine-tuned life indeed confirms the existence of a multiverse (at least in a suitably idealized setting). This convergence is no accident: we present two theorems showing that in this setting, *any* updating rule that satisfies a few reasonable conditions will have the same feature. The conclusion that fine-tuned life provides evidence for a multiverse is hard to escape

Counting Your Chickens

Suppose that, for reasons of animal welfare, it would be better if everyone stopped eating chicken. Does it follow that you should stop eating chicken? Proponents of the “inefficacy objection” argue that, due to the scale and complexity of markets, the expected effects of your chicken purchases are negligible. So the expected effects of eating chicken do not make it wrong. We argue that this objection does not succeed, in two steps. First, empirical data about chicken production tells us that the expected effects of consuming *many* chickens are not negligible. Second, this implies that the expected effect of consuming one chicken is ordinarily not negligible. *Parity* between your purchase and other counterfactual purchases and *uncertainty* about others’ consumption behavior each tend to pull the expected effect of a single purchase toward the average large scale effect. While some purchases do have negligible expected effects, many do not

Decision Theory and Deep Ignorance

Decision theory is about making choices under conditions of uncertainty. I argue that traditional decision theories overlook uncertainty about oneself––that they offer inadequate guidance to agents lacking self-knowledge. I develop alternative theories that do better

Fine-tuning Fine-tuning

This chapter argues that the fine-tuning argument for the existence of God is a straightforwardly legitimate argument. The fine-tuning argument takes certain features of fundamental physics to confirm the existence of God because these features of fundamental physics are more likely given the existence of God than they are given the non-existence of God. And any such argument is straightforwardly legitimate, as such arguments follow a canonically legitimate form of empirical argumentation. The chapter explores various objections to the fine-tuning argument: that it requires an ill-defined notion of small changes in the laws of physics, that it over-generalizes, that it requires implausible presuppositions about divine intentions, and that it is debunked by anthropic reasoning. In each case it finds either that the putatively objectionable feature of the fine-tuning argument is inessential to it or that the putatively objectionable feature of the fine-tuning argument is not actually objectionable