[StAthanasiustheGreat]

Or maybe because of the theological fault AND they represented a threat to Rome. Just a possibility that the religious reasons stated for the Crusade were actually genuine.

[Mad Dawg]

I think it very likely that we'll never know precisely what the Albigensians believed. On the other hand, I bet it's even harder to demonstrate that the Church's concern was ONLY a matter of ecclesiology or church polity. The same care which leads reasonable people to doubt the standard accounts of Cathar theology and metaphysics ought also to lead them to acknowledge that the "real" reason for the Church's response is unknown.

It's more than a little ridiculous to be all scholarly and responsible about the unknowability of Cathar thought and then, minutes later, to pretend to knowledge of all the whys and wherefores of the Catholic response.