Harmonious four-dimensionalist endurantism

I articulate a new version of the view that reality consists of temporally extended simples, which is immune to the argument from vagueness for temporal parts and is perfectly compatible with diachronic universalism. Following Josh Parsons’s classification of views about persistence, I take this to be a four-dimensionalist form of endurantism (4DE, for short). What’s distinctive about my version of 4DE is that it incorporates an independently plausible harmony principle about temporal location. I formulate the relevant harmony principle and show that it affords 4DEists a novel, principled way of resisting the argument from vagueness, and ensures that their view is in fact perfectly compatible with unrestricted diachronic composition.