It would seem, then, that the fourth century witnessed the establishment, both at Rome and elsewhere, of Christmas and Epiphany as two distinct feasts, whereas only one, although probably not everywhere the same one, had been known before. This fact is hardly to be explained by a mere attempt to accommodate varying local uses. The tradition of the Armenian doctors, who stood out against Christmas, asserts that their opponents removed the birthday of Christ from January 6 out of ‘disobedience[838].’ This points to a doctrinal reason for the separate celebration of the birth and the baptism. And such a reason may perhaps be found in the Adoptionist controversies. The joint feast appeared to lend credence to the view, considered a heresy, but still adhered to by the Armenian Church, that Christ was God, not from his mother’s womb, but only from his adoption or spiritual birth at the baptism in Jordan. It was needful that orthodox Christians should celebrate him as divine from the very moment of his carnal birth[839]. The choice of December 25 as the day for the Roman feast cannot be supposed to rest upon any authentic tradition as to the historic date of the Nativity. It is one of several early patristic guesses on the subject. It is not at all improbable that it was determined by an attempt to adopt some of the principal Christian festivals to the solstices and equinoxes of the Roman calendar[840]. The enemies of Roman orthodoxy were not slow to assert that it merely continued under another name the pagan celebration of the birthday of _Sol Invictus_[841]. Nor was the suggestion entirely an empty one. The worshippers of _Sol Invictus_, and in particular the Mithraic sect, were not quite on the level of the ordinary pagans by tradition. Mithraism had claims to be a serious and reasonable rival to Christianity, and if its adherents could be induced by argument to merge their worship of the physical sun in that of the ‘Sun of Righteousness,’ they were well worth winning[842]. On the other hand there were obvious dangers in the Roman policy which were not wholly averted, and we find Leo the Great condemning certain superstitious customs amongst his flock which it is difficult to distinguish from the sun-worship practised alike by pagans and by Saint Augustine’s heretical opponents, the Manichaeans[843].