Peter van Inwagen’s Special Composition Question asks, What are the necessary and sufficient conditions for some given things to compose something? David Lewis and Ted Sider argue that since a restriction on composition has to be either arbitrary or vague, composition is unrestricted; any collection of objects has a sum. To maintain his restrictive thesis that some things compose an object if and only if their activity constitutes a life, which is a vague criterion, van Inwagen embraces a three-valued logic. Trenton Merricks, on the other hand, proposes a restriction which aims to be both non-arbitrary and precise; necessarily, all and only composites have causal powers which are irreducible to the powers or properties of their proper parts. However, there are borderline cases of having non-redundant causal powers; so Merricks’ criterion is not precise. Defenders of restrictive composition should follow van Inwagen’s example in making use of the resources of non-classical logic.