Brute fact parsimony

Abstract This paper argues that two of the theoretical virtues—ontological and ideological parsimony—reduce to a more foundational and familiar theoretical imperative to avoid positing brute facts. Following recent developments in metaphysics, I characterize ontological and ideological parsimony as principles that impose theoretical costs on fundamental ontology and primitive ideology respectively. I subsequently argue that both sorts of theoretical commitment entail costly brute (i.e., ungrounded) commitments. We can thus understand ontological and ideological parsimony as reducing to brute fact parsimony . After defending this proposal against objections, I extend it to the non-fundamental by introducing the notion of domain-relative bruteness, thereby explaining parsimony’s role in the special sciences. If my argument is successful, then it is now possible to weigh previously incommensurable virtues against each other. I suggest that this may facilitate progress in the debate about the laws of nature.