Reference models of the earth’s interior play an important role in the acquisition of knowledge about the earth’s interior and the earth as a whole. Such models are used as a sort of standard reference against which data are compared. I argue that the use of reference models merits more attention than it has gotten so far in the literature on models, for it is an example of a method of doing science that has a long and significant history, and a study of reference models could increase our understanding of this methodology.

In this discussion note, we explain how to relax some of the standard assumptions made in Garber-style solutions to the Problem of Old Evidence. The result is a more general and explanatory Bayesian approach.

This article introduces and motivates the notion of a “properly extensive” quantity by means of a puzzle about the reliability of certain canonical length measurements. An account of these measurements’ success, I argue, requires a modally robust connection between quantitative structure and mereology that is not mediated by the dynamics and is stronger than the constraints imposed by “mere additivity.” I outline what it means to say that length is not just extensive but properly so and then briefly sketch an application of proper extensiveness to the project of providing a reductive ground for metric quantitative structure.

Naturalized metaphysicians defend the thesis that science licenses metaphysics, such that only metaphysical results based on the best science are legitimate. This view is problematic, due to the fact that the reasons they identify for such license are apparently self-defeating. Anjan Chakravartty defends a revised approach to understanding the licensing relation. I argue that the proposed response is a step forward on behalf of naturalizing metaphysics but still does not take seriously the contention that science involves, inextricably, a contribution from the a priori. I conclude by considering what options the naturalized metaphysician is left with.

Kyle Stanford’s reformulation of the problem of underdetermination has the potential to highlight the epistemic obligations of scientists. Stanford, however, presents the phenomenon of unconceived alternatives as a problem for realists, despite critics’ insistence that we have contextual explanations for scientists’ failure to conceive of their successors’ theories. I propose that responsibilist epistemology and the concept of “role oughts,” as discussed by Lorraine Code and Richard Feldman, can pacify Stanford’s critics and reveal broader relevance of the “new induction.” The possibility of unconceived alternatives pushes us to question our contemporary expectation for scientists to reason outside of their historical moment.