 When first introducing the doctrine of Vision in God in the Search, however, he takes a different tack. There he presents a negative, or eliminative, argument in which he enumerates five competing theories of how material objects are known, and then systematically eliminates each one until only Vision in God remains. For such an argument to succeed, one must ensure that the enumeration is complete – that it exhausts all possible theories. Malebranche clearly thinks that he satisfies this requirement, though critics from John Locke onwards have complained that it does not. Some recent commentators have attempted to show why Malebranche’s enumeration is, indeed, complete or at least why he thinks it is (Connell 1967, 162; Nadler 1992, 138–140).