Parsimony and internal complexity

I argue in favour of a novel conception of ontological parsimony. According to this novel conception, ontological parsimony qua theoretical virtue should not be measured solely by the number of entities (or kinds of entities, or fundamental kinds of entities) posited, but also by the internal complexity of those entities. I argue for this claim via the familiar methodology of appealing to intuitions about particular cases and to observations about successful scientific methodology. I furthermore point out some implications of my argument for other debates, and suggest a method for rendering parsimony qua degree of internal complexity commensurable with traditional conceptions of parsimony.