Research in education and cognitive development suggests that explaining plays a key role in learning and generalization: when learners provide explanations even to themselves they learn more effectively and generalize more readily to novel situations. This paper explores a potential mechanism underlying this effect, motivated by philosophical accounts of the structure of explanations: that explaining guides learners to interpret observations in terms of unifying patterns or regularities, which in turn promotes the discovery of broad generalizations. Experiment 1 finds that prompting participants to explain while learning artificial categories promotes the induction of a broad generalization underlying category membership. Experiment 2 suggests that explanation most readily prompts discovery in the presence of anomalies: observations inconsistent with current beliefs. Experiment 1 additionally suggests that explaining might result in reduced memory for details. These findings provide evidence for the proposed mechanism and insight into the potential role of explanation in discovery and generalization.