Hempel in Aspects of Scientific Explanation and Other Essays tells us that “all scientific explanation involves, explicitly or by implication, a subsumption of its subject matter under general regularities; that it seeks to provide a systematic understanding of empirical phenomena by showing that they fit into a nomic nexus.” This I take to be an informal statement of his covering-law, “model” of scientific explanation. In defense of his “model” against apparent examples of scientific explanations which do not fit it, Hempel's almost instinctive reaction has been to patch them up in some way so that they do conform. This, I believe, is the wrong way to defend the covering-law “model”. In the three parts of this brief essay I shall do the following: (1) show that Hempel's attempt to patch up a certain version of so-called “rational” explanation does not succeed of its purpose, (2) generalize that result with respect to all dispositional explanations, and (3) reflect momentarily on philosophic method and another way to defend the covering-law “model”.