The practice of not being married, among those in major orders in the Church. Voluntary celibacy among the clergy goes back to the first century of the Christian era. In time, two different traditions arose in the Catholic Church. In the East, the tendency was toward having a married clergy, and as early as the Council of Nicaea (A.D. 325) the proposal to make celibacy obligatory on all the clergy was not accepted. The canonical position, in general, is that priests and deacons may marry before ordination but not after. Bishops, however, must be celibate. In the West, the canonical position of the Church has remained constant from as early as the Spanish Council of Elvira (A.D. 306). In 386, Pope St. Siricius ordered celibacy for "priests and Levites." The same legislation was passed by Pope St. Innocent I (reigned 402-17). In spite of numerous failures in observance, and even concerted opposition in some quarters, the Catholic Church has remained constant in her teaching on clerical celibacy. Enacted into canon law in 1918, the legislation was not changed by the Second Vatican Council. In its Decree on the Ministry and Life of Priests, it declared, "Celibacy was first recommended to priests. Then, in the Latin Church, it was imposed by law on all who were to be promoted to sacred orders. This legislation, to the extent to which it concerns those who are destined for the priesthood, this most holy Synod once again approves and confirms" (Presbyterorum Ordinis, III, 16). When a man is ready for the diaconate, he is ordained either to the transient diaconate with a view to the priesthood or to the permanent diaconate. If he is going on to the priesthood, he binds himself to celibacy for life. If he is to become a permanent deacon, and is unmarried, he also binds himself to celibacy, and cannot marry in the future, although he can later become a priest. If he is a married man, he may be ordained to the permanent diaconate. Then, should his wife die, he must remain unmarried and may go on for the priesthood.