@BowsacNoodle @ArdainianRight @hachi @djsumdog @meowski @mrsaturday
That's what Catholic Christians were - the winning side of an early theological conflict. But that's not a basis of truth, or a reason to hold their interpretations or choice of canon as special from Valentinus' or Marcion's.

Funnily enough before I labelled C.S Lewis a heretic for his ecumenism, that he picked too few things to be his fundamentals. Now I think he picked too many, as Adoptionism is a reasonable interpretation of Mark, for instance.
What constitutes heresy is entirely subjective and depends on the current Christian group you believe is true, appealing to it doesn't help.