ABSTRACT
Intuitively, some things compose further objects: atoms compose human beings (equivalently, and perhaps more naturally, human beings are composed of atoms). Intuitively, some things do not compose further objects: myself and Brad Pitt’s left arm do not compose some monstrosity that has three arms – we are just two different things, a person and an arm, that do not compose anything. van Inwagen (1990) famously demanded to know when this happens: under what circumstances do things go on to compose a further thing? This question is called the Special Composition Question.
