Conventionality, underdetermination and the inter-theory transport of concepts

This thesis investigates two kinds of conventionalism in the context of two issues in the philosophy of spacetime: the Einstein Algebra formulation of General Relativity (GR) and the status of simultaneity in special relativity. The outcome of the analysis is that these two cases pull in different directions: I take a step back and analyse the strategy of breaking underdetermination by the invocation of what is often thought of as “non-epistemic” virtues. I argue that certain such virtues are more epistemically relevant than previously thought, in particular where these virtues have to do with the ability of a theory to “point ahead” towards new theories. This conclusion is that the underdetermination between the two formulations of GR only prima facie requires breaking by convention. On the other hand, a careful appraisal of the relativistic limit of Minkowski spacetime leads to the conclusion that relativistic simulaneity is in a precise sense so conventional so as to be devoid of content.