Can opium's tendency to induce sleep be explained by appeal to a "dormitive virtue"? If the label merely references the tendency being explained, the explanation seems vacuous. Yet the presence of a label could signal genuinely explanatory content concerning the (causal) basis for the property being explained. In Experiments 1 and 2, we find that explanations for a person's behavior that appeal to a named tendency or condition are indeed judged to be more satisfying than equivalent explanations that differ only in omitting the name. In Experiment 3, we find support for one proposal concerning what it is about a name that drives a boost in explanatory satisfaction: named categories lead people to draw an inference to the existence of a cause underlying the category, a cause that is responsible for the behavior being explained. Our findings have implications for theories of explanation and point to the central role of causation in explaining behavior.