 Another example concerns composition. Some people—those who believe in “unrestricted mereological composition”—think that any two or more things whatsoever compose a larger thing. They typically claim that while the (single) fusion is not identical to its (many) parts (the exception is Baxter 1988), it does supervene on them, and is thus “nothing over and above” those parts. So, for example, there is a mereological fusion of your left elbow, Tony Blair, and the Mississippi River, and it is distinct from, but nothing over and above, those three parts. Lewis, speaking of a fusion of a trout and a turkey, says that “it is neither fish nor fowl, but it is nothing else: it is part fish and part fowl” (1991, 80) and that “mereology is innocent” (87). However, opponents of unrestricted mereological composition are unsurprisingly unconvinced: “what does ‘nothing over and above’ mean? This slippery phrase has had a lot of employment in philosophy, but what it means is never explained by its employers” (van Inwagen 1994, 210). Indeed, the thought that composition is not in the least ontologically innocent has led some to claim that there aren’t any composite objects (or that living organisms are the only composite objects; see van Inwagen 1990, Merricks 2001, Dorr and Rosen 2002, and the entry on  mereology).