Fragments of a Faith Forgotten, by G.R.S. Mead, , at sacred-texts.com
The Master of Marcion.LET us now return to the historical twilight of the second century, and turn our attention to the great Basilidian and Valentinian developments. But before doing so, it will be convenient to give a brief sketch of the great and contemporaneous Marcionite movement, which at one time threatened to absorb the whole of Christendom. The method of this school was the direct prototype of the method of modern criticism. Its conclusions, however, were far more sweeping; for it not only rejected the Old Testament entirely, but also the whole of the documents of the "in order that it might be fulfilled" school of Gospel-compilation.
The predecessor of Marcion is said to have been a certain Cerdo, of Syrian extraction, who flourished at Rome about 135 A.D. But the fame of Marcion so eclipsed the name of his preceptor, that Patristic writers frequently confuse not only their teachings but even the men themselves. It is interesting to note that, though Cerdo's relationship with the Church of Rome was unsettled, no distinct sentence of
excommunication is recorded against him; it would, therefore, appear that the idea of a rigid canon of orthodoxy was not yet developed even in the exclusive mind of the Roman presbytery. It was no doubt the success of Marcion that precipitated the formulation of the idea of the canon in the mind of the Roman church, the pioneer of subsequent orthodoxy.