According to First-Person Realism, one's own first-person perspective on the world is metaphysically privileged in some way. After clarifying First-Person Realism by reference to parallel debates in the metaphysics of modality and time, I survey eight different arguments in favor of First-Person Realism.

Does the evidence that our universe contains fine-tuned life confirm the multiverse hypothesis? The answer depends on our approach to self-locating beliefs. In a recent paper, Isaacs, Hawthorne, and Russell (2022) offer two arguments for thinking that such evidence does confirm the multiverse hypothesis. First, they argue that the three leading approaches to self-locating beliefs all entail that such evidence confirms the multiverse hypothesis. Second, they present a pair of theorems showing that any approach to self-locating beliefs that satisfies certain (...) “reasonable” constraints will entail that such evidence confirms the multiverse hypothesis. I argue that Isaacs, Hawthorne, and Russell’s two arguments are not compelling, the first because they fail to consider some natural approaches to self-locating beliefs, the second because their theorems rely on a suspect premise that we should reject. Contra Issacs, Hawthorne, and Russell, I argue that on a natural approach to self-locating beliefs the evidence that our universe contains fine-tuned life needn’t confirm the multiverse hypothesis. (shrink)

A Boltzmann brain is a randomly-formed configuration of matter that is conscious. According to some theories that cosmologists take seriously, the universe is so spatiotemporally large that it contains a great many Boltzmann brains that are duplicates of you. In the light of this it seems to follow that you should have significant confidence that you are a Boltzmann brain. What's worse, your situation seems to be "cognitively unstable": It seems unstable to end up confident that you are a Boltzmann (...) brain because you should then think that your apparent cosmological evidence was randomly generated and hence that your confidence was unwarranted. But it also seems unstable to end up confident that you are not a Boltzmann brain because then you should follow your cosmological evidence to the conclusion that many Boltzmann brain duplicates of you exist, and hence that you are probably a Boltzmann brain. -/- A case involving unreliable vision exhibits a similar threat of instability. A simple Bayesian model of that case, however, shows that the threat is an illusion. And a corresponding model suggests that the same goes for the threat of instability associated with Boltzmann brains. (shrink)

According to the principle of indifference, when a set of possibilities is evidentially symmetric for you – when your evidence no more supports any one of the possibilities over any other – you're required to distribute your credences uniformly among them. Despite its intuitive appeal, the principle of indifference is often thought to be unsustainable due to the problem of multiple partitions: Depending on how a set of possibilities is divided, it seems that sometimes, applying indifference reasoning can require you (...) to assign incompatible credences to equivalent possibilities. This paper defends the principle of indifference from the problem of multiple partitions by offering two guides for how to respond. The first is for permissivists about rationality, and is modeled on permissivists' arguments for the claim that a body of evidence sometimes does not uniquely determine a fully rational credence function. The second is for impermissivists about rationality, and is modeled on impermissivists' arguments for the claim that a body of evidence does always uniquely determine a fully rational credence function. What appears to be a decisive objection against the principle of indifference is in fact an instance of a general challenge taking different forms familiar to both permissivists and impermissivists. (shrink)