Metaphysicians now typically distinguish between a theory’s ontology and its ideology. But besides a few cursory efforts, no one has explained the role of ideology in theory choice. In this paper I develop a framework for discussing how differing approaches to ideology impact metaphysical disputes. I first provide an initial characterization of ideology and develop two contrasting types of criteria used to evaluate its quality. In using externalist criteria, we judge the quality of a theory’s ideology by its relation to (...) external features of the world. In contrast, in using internalist criteria, we judge the quality of a theory’s ideology by features internal to the theory and the theorizer, e.g. the intelligibility of the terminology employed. I then argue for an unrestricted application of externalist criteria, what I call maximal realism. According to maximal realism, we ought to apply externalist criteria to the entirety of a theory’s ideology—to not only predicates but also to quantifiers and logical operators. I defend maximal realism from what I take to be the best objection to it: that the view leads to bad questions. As part of my defense, I argue that those who would restrict their application of externalist criteria either adopt an unjustified partition of ideology or reject seemingly benign questions. Finally, I apply my discussion of ideology to two extant metaphysical disputes. (shrink)