 The claim that purely holist explanations are in need of microfoundations may be qualified in various ways. Sometimes, it is made clear that purely holist explanations should always be accompanied by accounts of the underlying individual-level mechanisms. Very often, this position is motivated by appeal to the “mechanism model” of explanation. It states that to explain is to show how one phenomenon, via underlying mechanisms, brought about another phenomenon; to borrow Elster’s words, to explain is “to provide a mechanism, to open up the black box and show the nuts and bolts, the cogs and wheels” (Elster 1985: 5). Accordingly, purely holist explanations do not actually constitute explanations unless they are supplemented by accounts of the underlying individual-level mechanisms. In other instances, it is only held that purely holist explanations must be supplemented by accounts of the underlying individual-level mechanisms in order to qualify as satisfying or complete explanations. This view is commonly motivated by a weaker version of the mechanism model of explanation, according to which a satisfactory or complete explanation, rather than an explanation as such, must describe how one phenomenon, via underlying mechanisms, brought about another.