Although there appears to be a lot in common between Ovid’s Fasti and Metamorphoses in terms of how they connect the present to the past through aetiology, the chapter argues that in fact there are profound differences in the role of aetiology in each poem. The Fasti is full of examples of past actions that have become fixed in a form that endures in current ritual, but there are vanishingly few examples of ritual aetiology in the Metamorphoses. The Fasti is really about religion while the Metamorphoses is really about mythology. Even though scholars of religion in both the ancient and modern worlds have seen a tight connection between myth and ritual, the chapter argues that we should follow Ovid in disavowing the myth/ritual nexus.