 In the literature on material objects, an oft-discussed question is: when do two or more things compose a further thing (van Inwagen 1990)? Some common answers are—never (Compositional Nihilism—Unger 1979, Dorr and Rosen 2002); always (Mereological Universalism—Lewis 1986, pp. 212–213; Rea 1998); only when they form a life (Organicism—van Inwagen 1990; Merricks 2001); whenever the candidate fusion has non-redundant causal powers (Merricks 2001); whenever (and only whenever) we intuitively think they do (Intuitivism—Commonsense); or that composition is a brute fact (Brutalism—Markosian 1998b). And the answers have  proliferated.[15]