In ecclesiastical usage the term denotes the renunciation on oath of heresy, made when the penitent is reconciled with the church. Gregory the Great (d.604) had occasion to set out the practice of the early church when it dealt with heretics such as Montanists, Eunomians, and others. There was added to the abjuration a solemn profession of faith, especially after the rise of Nestorianism* and Eutychianism.* The procedure was further elaborated during the time of the Inquisition,* according to the degree of heresy. In modern times abjuration in its formal sense is normally restricted to receptions into, or reconciliation with, Greek and Roman Catholic churches.