Abstract

One of the core charges against explanationist scientific realism is that is too epistemically optimistic. Taking the charge seriously, some realists offer alternative forms of scientific realism – semi-realism and theoretical irrealism – designed to be more modestin their epistemic claims. In this paper, I consider two cases in cosmology and astrophysics that raise novel issues for both views: semi-realism is argued to end up making astrophysics metaphysically inflated when confronted with cases regarding the existence and evolution of galaxies and other astrophysical objects that cross the cosmic event horizon; theoretical irrealism is argued to be in serious tension with standard evidential reasoning in the context of the dark matter problem.