Title: “Good News for the Subregion Theory of Parthood”

Abstract: The Subregion Theory of Parthood is probably the most intuitive theory of parthood. It says that whatever is exactly located at a subregion of your exact location is part of you, and nothing else is. Mutatis mutandisfor all material objects. I defend this view from its two worst enemies: colocation and interpenetration. It is inconsistent with colocation, but I argue that colocation is (at least physically) impossible. Some have alleged that it is inconsistent with interpenetration, but I complicate matters by showing that it is inconsistent with some but not all cases of interpenetration. Fortunately, those cases are all also (at least physically) impossible. This is good news for the Subregion Theory of Parthood, which looks more compelling for having defeated its worst enemies.