Oh no, someone's asking about Catharism. What constituted the heretical beliefs that have traditionally been described as "Catharism" is one of the most genuinely vicious debates among medieval historians. There are historians who think Catharism didn't exist, and there are historians that want to punch those people. It's the medieval equivalent of asking a Lord of the Rings fan if Balrog has wings. We have a few threads going into this debate.

How did Catharism start, develop and become so popular in southern Fance? with a variety of contributors, and some examples of how its basically impossible to have a lengthy discussion of Catharism that doesn't threaten to descend into incivility.

Is there currently any consensus among historians as to whether or not the Cathars and the Cathar Church actually existed? with contributions by u/qed1

Catharism: was it a thing? with many contributors.

But frankly, we don't know. We know there was a significant number of heretics kicking about southern France c.1200, who may have been slightly organised, and we have traditionally called them Cathars. There are some later heretics in Italy that are sometimes called Cathars. The threads go into why that is questioned, what the so-called "Cathars" may or may not have believed, and the extent to which they may or may not have been organised. But we can't be certain of anything. It's one of those situations where there's enough source material to get a discussion going, but nowhere near enough source material to reach a consensus on wtf was actually going on.