The Title of this Oration has given rise to a doubt whether it was preached on Dec. 25, 380, or on Jan. 6, 381.  The word Theophania is well known as a name for the Epiphany; which, however, according to Schaff, H. E., Nic. Per., p. 399. was originally a celebration both of the Nativity and the Baptism of our Lord.  The two words seem both to have been used in the simplest sense of the Manifestation of God, and certainly were applied to Christmas Day.  Thus Suidas, “The Epiphany is the Incarnation of the Saviour;” and Epiphanius (Hær., 53), “The Day of the Epiphany is the day on which Christ was born according to the flesh.”  But S. Jerome applies the word to the Baptism of Christ; “The day of the Epiphany is still venerable; not, as some think, on account of His Birth in the flesh; for then He was hidden, not manifested; but it agrees with the time at which it was said, This is My beloved Son (In Ezech. I.).  There is also a Sermon, attributed to S. Chrysostom, “On the Baptism of Christ,” in which it is expressly denied that the name Theophany applies to Christmas.  The Oration itself, however, contains evidence to shew that the Festival of our Lord’s Birth was kept at the earlier date; for in c. 16 the Preacher says, “A little later you shall see Jesus submitting to be purified in the river Jordan for my purification.”  And another piece of evidence occurs in the oration In Sancta Lumina, c. 14, “At His Birth we duly kept festival, both I the leader of the feast, and you.  Now we are come to another action of Christ and another Mystery.”