Perfect was the name given by Bernard of Clairvaux to the leaders of the mediaeval Christian religious movement in southern France and northern Italy commonly referred to as the Cathars. The Perfecti were not clerics in any way, but merely members who had become 'adepts' in the teaching, and whose role was that of aiding other ordinary members achieve the rewards of belief and practice. The term reflects the fact that such a person was seen by the Catholic Church as the "perfect heretic". As "bonhommes", Perfecti were expected to follow a lifestyle of extreme austerity and renunciation of the world which included abstaining from eating meat and avoiding all sexual contact. They were thus recognized as trans-material angels by their followers, the Credentes. Perfecti were drawn from all walks of life and counted aristocrats, merchants and peasants among their number. Women could also become Perfecti and were known as Parfaites or Perfectae.

Catharism was a Christian quasi-dualist or pseudo-Gnostic movement which thrived in Southern Europe, particularly in northern Italy and southern France, between the 12th and 14th centuries. Denounced as a heretical sect by the Catholic Church, its followers were attacked first by the Albigensian Crusade and later by the Medieval Inquisition, which eradicated the sect by 1350. Many thousands were slaughtered, hanged, or burnt at the stake, sometimes without regard for "age or sex."