the Italian Natale, and the Welsh Nadolig, all obviously derived from the Latin natalis, and meaning " birthday." One naturally takes this as referring to the Birth of Christ, but it may at any rate remind us of another birthday celebrated on the same date by the Romans of the Empire, that of the unconquered Sun, who on December 25, the winter solstice according to the Julian calendar, began to rise to new vigour after his autumnal decline.
Why, we may ask, did the Church choose December 25 for the celebration of her Founder's Birth ? No one now imagines that the date is supported by a reliable tradition ; it is only one of various guesses of early Christian writers. As a learned eighteenth-century Jesuit 2° has pointed out, there is not a single month in the year to which the Nativity has not been assigned by some writer or other. The real reason for the choice of the day most probably was, that upon it fell the pagan festival just mentioned.
The Dies Natalis Invicti was probably first celebrated in Rome by order of the Emperor Aurelian (270-5), an ardent worshipper of the Syrian sun-god Baal.21 With the Sol Invictus was identified the figure of Mithra, that strange eastern god whose cult resembled in so many ways the worship of Jesus, and who was at one time a serious rival of the Christ in the minds 01 thoughtful men.* 22 It was the sun-god, poetically and philosophically conceived, whom the Emperor Julian made the centre of his ill-fated revival of paganism, and there is extant a fine prayer of his to " King Sun." 23
What more natural than that the Church should choose this day to celebrate the rising of her Sun of Righteousness with healing in His wings, that she should strive thus to draw away to His worship some adorers of the god whose svmbol and representative was the earthly sun ! There is no direct evidence or deliberate substitution, but at all events ecclesiastical writers soon after the foundation of Christmas made good use of the idea
* Mithraism resembled Christianity in its monotheistic tendencies, its sacraments, its comparatively high morality, its doctrine of an Intercessor and Redeemer, and its vivid belief in a future life and judgment to come. Moreover Sunday was its holy-day dedicated to the Sun.