It goes without saying THAT I DON'T BELIEVE the claims about the author being responsible for the original edition. So he made up a story based on something. That someone in Tatian's circle was responsible for an Against Marcion is clear from Eusebius:
4.16.7. And that he met his death as he had predicted that he would, in consequence of the machinations of Crescens, is stated by Tatian, a man who early in life lectured upon the sciences of the Greeks and won no little fame in them, and who has left a great many monuments of himself in his writings. He records this fact in his work against the Greeks, where he writes as follows: And that most admirable Justin declared with truth that the aforesaid persons were like robbers.
8. Then, after making some remarks about the philosophers, he continues as follows: Crescens, indeed, who made his nest in the great city, surpassed all in his unnatural lust, and was wholly devoted to the love of money.
9. And he who taught that death should be despised, was himself so greatly in fear of it that he endeavored to inflict death, as if it were a great evil, upon Justin, because the latter, when preaching the truth, had proved that the philosophers were gluttons and impostors. And such was the cause of Justin's martyrdom.
4.28 And as for Musanus, whom we have mentioned among the foregoing writers, a certain very elegant discourse is extant, which was written by him against some brethren that had gone over to the heresy of the so-called Encratites, which had recently sprung up, and which introduced a strange and pernicious error. It is said that Tatian was the author of this false doctrine.
1. He is the one whose words we quoted a little above in regard to that admirable man, Justin, and whom we stated to have been a disciple of the martyr. Irenæus declares this in the first book of his work Against Heresies, where he writes as follows concerning both him and his heresy:
2. Those who are called Encratites, and who sprung from Saturninus and Marcion, preached celibacy, setting aside the original arrangement of God and tacitly censuring him who made male and female for the propagation of the human race. They introduced also abstinence from the things called by them animate, thus showing ingratitude to the God who made all things. And they deny the salvation of the first man.
3. But this has been only recently discovered by them, a certain Tatian being the first to introduce this blasphemy. He was a hearer of Justin, and expressed no such opinion while he was with him, but after the martyrdom of the latter he left the Church, and becoming exalted with the thought of being a teacher, and puffed up with the idea that he was superior to others, he established a peculiar type of doctrine of his own, inventing certain invisible æons like the followers of Valentinus, while, like Marcion and Saturninus, he pronounced marriage to be corruption and fornication. His argument against the salvation of Adam, however, he devised for himself. Irenæus at that time wrote thus.
4. But a little later a certain man named Severus put new strength into the aforesaid heresy, and thus brought it about that those who took their origin from it were called, after him, Severians.
5. They, indeed, use the Law and Prophets and Gospels, but interpret in their own way the utterances of the Sacred Scriptures. And they abuse Paul the apostle and reject his epistles, and do not accept even the Acts of the Apostles.
6. But their original founder, Tatian, formed a certain combination and collection of the Gospels, I know not how, to which he gave the title Diatessaron, and which is still in the hands of some. But they say that he ventured to paraphrase certain words of the apostle, in order to improve their style.
7. He has left a great many writings. Of these the one most in use among many persons is his celebrated Address to the Greeks, which also appears to be the best and most useful of all his works. In it he deals with the most ancient times, and shows that Moses and the Hebrew prophets were older than all the celebrated men among the Greeks. So much in regard to these men.
5.13 Rhodo and his Account of the Dissension of Marcion.
1. At this time Rhodo, a native of Asia, who had been instructed, as he himself states, by Tatian, with whom we have already become acquainted, having written several books, published among the rest one against the heresy of Marcion. He says that this heresy was divided in his time into various opinions; and while describing those who occasioned the division, he refutes accurately the falsehoods devised by each of them.
2. But hear what he writes:
Therefore also they disagree among themselves, maintaining an inconsistent opinion. For Apelles, one of the herd, priding himself on his manner of life and his age, acknowledges one principle, but says that the prophecies are from an opposing spirit, being led to this view by the responses of a maiden by name Philumene, who was possessed by a demon.
3. But others, among whom are Potitus and Basilicus, hold to two principles, as does the mariner Marcion himself.
4. These following the wolf of Pontus, and, like him, unable to fathom the division of things, became reckless, and without giving any proof asserted two principles. Others, again, drifting into a worse error, consider that there are not only two, but three natures. Of these, Syneros is the leader and chief, as those who defend his teaching say.
5. The same author writes that he engaged in conversation with Apelles. He speaks as follows:
For the old man Apelles, when conversing with us, was refuted in many things which he spoke falsely; whence also he said that it was not at all necessary to examine one's doctrine, but that each one should continue to hold what he believed. For he asserted that those who trusted in the Crucified would be saved, if only they were found doing good works. But as we have said before, his opinion concerning God was the most obscure of all. For he spoke of one principle, as also our doctrine does.
6. Then, after stating fully his own opinion, he adds:
When I said to him, Tell me how you know this or how can you assert that there is one principle, he replied that the prophecies refuted themselves, because they have said nothing true; for they are inconsistent, and false, and self-contradictory. But how there is one principle he said that he did not know, but that he was thus persuaded.
7. As I then adjured him to speak the truth, he swore that he did so when he said that he did not know how there is one unbegotten God, but that he believed it. Thereupon I laughed and reproved him because, though calling himself a teacher, he knew not how to confirm what he taught.
8. In the same work, addressing Callistio, the same writer acknowledges that he had been instructed at Rome by Tatian. And he says that a book of Problems had been prepared by Tatian, in which he promised to explain the obscure and hidden parts of the divine Scriptures. Rhodo himself promises to give in a work of his own solutions of Tatian's problems. There is also extant a Commentary of his on the Hexæmeron.
9. But this Apelles wrote many things, in an impious manner, of the law of Moses, blaspheming the divine words in many of his works, being, as it seemed, very zealous for their refutation and overthrow.
So much concerning these.