Published online by Cambridge University Press: 01 January 2022
The Doomsday argument and anthropic reasoning are two puzzling examples of probabilistic confirmation. In both cases, a lack of knowledge apparently yields surprising conclusions. Since they are formulated within a Bayesian framework, they constitute a challenge to Bayesianism. Several attempts, some successful, have been made in a Bayesian framework that represents credal states by single credence functions to avoid these conclusions, but none of them can do so for all versions of the Doomsday argument. I show that adopting an imprecise framework of probabilistic reasoning allows for a more adequate representation of ignorance and explains away these puzzles.
This article stems from discussions at the UCSC-Rutgers Institute for the Philosophy of Cosmology in summer 2013. I am grateful to Chris Smeenk and Wayne Myrvold for discussions and comments on earlier drafts. For helpful discussions, I thank participants at the Imprecise Probabilities in Statistics and Philosophy workshop at the Munich Center for Mathematical Philosophy in June 2014 and at the Graduate Colloquium series at Western University. I used excerpts and results from this article in a subsequent paper: “The Bayesian Who Knew Too Much.”