One of Mill's primary targets, throughout his work, is intuitionism. In this paper, I distinguish two strands of intuitionism, against which Mill offers separate arguments. The first strand, a priorism, makes an epistemic claim about how we come to know norms. The second strand, ‘first principle pluralism’, makes a structural claim about how many fundamental norms there are. In this paper, I suggest that one natural reading of Mill's argument against first principle pluralism is incompatible with the naturalism that drives (...) his argument against a priorism. It must, therefore, be discarded. Such a reading, however, covertly attributes Mill realist commitments about the normative. These commitments are unnecessary. To the extent that Mill's argument against first principle pluralism is taken seriously, I suggest, it is an argument that points towards Mill as having an antirealist approach to the normative. (shrink)