Thus, notwithstanding all the rejection and calumniation of notable doctrinal innovations as heresies, foreign to the Church, even in the emergent Catholic Church itself, Christian doctrine was conceived in remodelled and new forms. This process of transformation, which continued through the centuries, in due course revealed itself impressively even in the paradoxical fate which befell heresy-hunting theologians of the early Catholic period. Many were stamped as heretics by the later Catholic Church or at least regarded by it, as old-fashioned eccentrics. In reality, if the newly developing Catholic Church be measured by the same rule by which it condemned other groups and tendencies as heretical, it is itself nothing other than a heresy, but certainly the most pregnant, which ultimately had driven triumphantly all others from the field. This victory it did not in the end even owe to the fact that it had simply fought the opposing heresies, but to the fact that it had taken over from them very positive and important suggestions, which it had then proceeded to convert after its own fashion to suitable means for its own new construction of doctrine.
Martin Werner, The formation of Christian Dogma, p. 51, 52.