 It is surprisingly difficult to find methodological reductionists among physicists. The elementary particle physicist Steven Weinberg, for example, is an avowed reductionist. He believes that by asking any sequence of deeper and deeper why-questions one will arrive ultimately at the same fundamental laws of physics. But this explanatory reductionism is metaphysical in so far as he takes explanation to be an ontic rather than a pragmatic category. On this view, it is not physicists but the fundamental laws themselves that explain why “higher level” scientific principles are the way they are. Weinberg (1992) explicitly distinguishes his view from methodological reductionism by saying that there is no reason to suppose that the convergence of scientific explanations must lead to a convergence of scientific methods.