Dallæus pointed out long ago, that ch. xiii abruptly interrupts the conclusion of the Epistle.
In what sense this chapter can be said to interrupt the conclusion it is difficult to say. It occupies exactly the place which would naturally be assigned to such personal matters; for it follows upon the main purport of the letter, while it immediately precedes the recommendation of the bearer and the final salutation. On the same showing the conclusion of the greater number of St Paul's Epistles is 'abruptly interrupted.'
5. The next argument is of another kind:--
The writer vehemently denounces, as already widely spread, the Gnostic heresy and other forms of false doctrine which did not exist until the time of Marcion, to whom and to whose followers he refers in unmistakable terms. An expression is used in ch. vii in speaking of these heretics, which Polycarp is reported by Irenæus to have actually applied to Marcion in person, during his stay in Rome about A.D. 160. He is said to have called Marcion 'the first-born of Satan,' ([Greek: prôtotokos tou Satana]), and the same term is employed in this Epistle with regard to every one who holds such false doctrines. The development of these heresies, therefore, implies a date for the composition of the Epistle, at earliest, after the middle of the second century, a date which is further confirmed by other circumstances.
I will take the latter part of this statement first, correcting however one or two errors of detail. M. Waddington's investigations, to which I have already alluded [115:1], oblige us to place Polycarp's visit to Rome some few years before 160, since his death is fixed at A.D. 155 or 156. Again, Irenæus does not state that the interview between Polycarp and Marcion took place at Rome. It may have taken place there, but it may have occurred at an earlier date in Asia Minor, of which region Marcion was a native [115:2]. These however are not very important matters. The point of the indictment lies in the fact that about A.D. 140, earlier or later, Polycarp is reported to have applied the expression 'first-born of Satan' to Marcion, while in the Epistle, purporting to have been written many years before, he appears as using this same expression of other Gnostic teachers. This argument is a good illustration of the reasons which satisfy even men like Lipsius and Hilgenfeld. To any ordinary judicial mind, I imagine, this coincidence, so far as it goes, would appear to point to Polycarp as the author of the Epistle; for the two facts come to us on independent authority--the one from oral tradition through Irenæus, the other in a written document older than Irenæus. Or, if the one statement arose out of the other, the converse relation of that which this hypothesis assumes is much more probable. Irenæus, as he tells us in the context, was acquainted with the Epistle, and it is quite possible that in repeating the story of Polycarp's interview with Marcion he inadvertently imported into it the expression which he had read in the Epistle. But the independence of the two is far more probable. As a fact, men do repeat the same expressions again and again, and this throughout long periods of their lives. Such forms of speech arise out of their idiosyncrasies, and so become part of them. This is a matter of common experience, and in the case of Polycarp we happen to be informed incidentally that he had a habit of repeating favourite expressions. Irenæus, in a passage already quoted, mentions his exclamation, 'O good God,' as one of these [116:1].