Sameness Relations

Abstract In this chapter, the author tops off their phasalist metaphysics with a phasalist account of sortal-relative sameness relations, i.e., an account of what it is to be the same φ. As one might expect, the phasalist metaphysics that emerges from the preceding chapters runs afoul of various substantialist intuitions. But if that metaphysics is supplemented with a suitable account of sameness relations, some of those intuitions can be vindicated after all. On the standard view of sameness relations, being the same φ reduces to numerical identity between φs. But the chapter presents an alternative view that amounts to a kind of stage theory for endurantists, where sortal-relative sameness relations reduce to counterpart relations between states of enduring material objects. This account of sameness relations is not required by any other elements of the author’s phasalist metaphysics. It is an optional add-on. The question is (roughly) whether it does enough work to pay its way. The chapter ends by exploring whether it does.