This contribution to a symposium "on the consequence of blur" deals with the case of Agustín de Ribera and his followers in sixteenth-century Castile. Inquisition trial records report the appearance, around 1535 among the Moriscos (Catholic converts of Muslim origin) in Toledo, of a boy who had ecstasies and visions in which he traveled to the Hereafter and received revelations. Though considered by his followers and also by the Inquisition a prophet of Muhammad, Agustin and his visions appear to have arisen in a context held in common with the Christian majority of Castile. This case thus reveals the existence of a hybrid form of Catholic Muslim religiosity, but only to scholars who do what is required to dedifferentiate—that is, to blur—the categories of identity and orthodoxy that were established by the Inquisition. Scholars have for too long allowed the Inquisition to overclarify for posterity the distinctions that existed between ethnoreligious groups and to define for us the nature of religious dissidence in early modern Spain.