Baum Levenbook explores another criticism made against legal positivism. As she explains, Mark Greenberg objects to legal positivism, first, that it is a mistake to hold that legal facts are determined solely by social facts and, second, that the content of authoritative pronouncements, such as statutes, is determined by their linguistic content. But, she points out, Greenberg’s first objection is premised on the mistaken assumption that the nature of law requires the connection between legal facts and the determinants of legal facts to be, as Greenberg puts it, ‘rationally intelligible’, and the second objection is based on the equally unwarranted assumption that it is part of the nature of law to operate in such a way as to ensure that legal obligations are genuinely binding.

It is widely accepted that it counts for a metaphysical theory when the theory is in accord with common sense and against a metaphysical theory when the theory clashes with common sense. It is unclear, however, why this should be the case. When engaging in metaphysics, why should we give common sense any weight? This chapter maintains that it is only against the backdrop of a particular metametaphysical stance that questions about metaphysical best practices become tractable. From the perspective of a metaphysics-as-modelling approach, common sense ought to play a significant, though defeasible, role in metaphysical theorizing. According with common sense is one of a number of theoretical virtues that metaphysicians should strive for. Nevertheless, it is important for the metaphysician to be cautious when appealing to common sense. She should distinguish what actually falls within the bounds of common sense as such from what a particular researcher happens to find intuitive. Furthermore, our best scientific theories may undercut the evidence provided by common sense. Finally, the metaphysician should attend to the context in which she invokes common sense. For some topics of inquiry, common sense ought to play a more expansive role in our metaphysical theorizing than for others.