Although Peter of les Vaux-de-Cernay's chronicle famously referred to the Cathar élite as perfecti at the opening of the Albigensian Crusade, the use of the term heretici perfecti is in fact extremely rare in the records of inquisitions. The Tuscan formulary very occasionally uses perfectus. Peter Cellan also uses it, but rarely – only for female full Cathars, and then only in a minority of cases. A 1256 deposition by William Fournier of Toulouse, quoted by Belhomme, gives another example: ‘the witness was and remains a hereticus indutus et perfectus’. However, Fournier's testimony is one of only a few examples that Arno Borst is able to give in his own footnote on this term, despite his extensive knowledge of inquisition material. In fact, two very large collections of depositions, those before Renous of Plassac and Pons of Parnac in 1272–8 in Doat volumes 25 and 26, and the register of Toulouse MS 609, which between them cover a wide span of the mid thirteenth century and contain references to a huge number of heretici, offer not a single instance in which those heretics are described as perfecti.

For the general reader, then, the widespread habit among modern historians of heresy of using ‘Perfect/Perfects’ as a noun to denote Cathar heretics creates an impression that is at odds with the infrequency with which it was used. More, it conjures the modern sense of the word, of ‘perfect’ as ‘best possible’, ‘flawless’ or ‘ideal’.