“O Mary, thou art all fair, unstained by original sin.” This cry of admiration, which the Church puts on our lips, expresses the feelings of mankind subject to the evil consequence of sin before the spotless purity of our Lady. From all eternity God has chosen Mary to be the Mother of the Word Incarnate; He therefore decked her in holiness, preserving her from all stain and making her a worthy dwelling for His Son. The Blessed Virgin’s perfect redemption which, from the moment of her conception, preserved her from original sin cannot, therefore, be dissociated from our redemption by Christ; and so, the feast of the Immaculate Conception, coming in the course of Advent, heralds the splendors of the Incarnation of the Redeemer. The feast was instituted by Pius IX when he defined the dogma on December 8, 1854. However, a feast of the “Conception” was celebrated long before; it is found in the East in the eighth century.