Epistemic Holes And Determinism In Classical General Relativity

Determinism fails easily if spacetimes with points removed from the spacetime manifold are taken to be physically reasonable representations of a way the world could be according to classical general relativity. I discuss a recently proposed condition for determining which spacetimes have holes-epistemic hole freeness-and show that (a) epistemic hole freeness gives the correct verdict in some (but not all) non-globally hyperbolic spacetimes with a closed subset removed, (b) certain spacetimes with genuinely indeterministic features count as having an epistemic hole, which implies that the requirement of epistemic hole freeness enforces a form of determinism, and (c) there is a large class of spacetimes that intuitively are radically indeterministic and unphysical due to containing a hole (of a kind), but are free from epistemic holes. I show that a few natural ways of remedying (c) are not satisfactory.