By Sacred Tradition is meant the revealed truths taught by Christ and His Apostles, which were given to the Church only by word of mouth and not through the Bible, though they were put in writing principally by the Fathers of the Church. In a wide sense Tradition embraces the whole teaching of the Church, including the Bible, since it is only from the Church that we have the Bible. In a stricter sense Tradition includes only what was handed down orally from the Apostles. The Apostles themselves say that there is much that they have delivered to the faithful by word of mouth (2 John 12; 1 Cor. 11:2). Among many examples of truths in Tradition, not clearly manifested in Holy scriptures, are: the exact number of sacraments, the time of institution of some sacraments, the books that make up the Bible, the Baptism of infants, and Sunday observance. All the truths of Sacred Tradition now have found their way into books. From the first Christian centuries the practices and doctrines of Tradition were preserved by saintly teachers whom we call Fathers of the Church. They were disciples of the Apostles, contemporaries of those disciples, or disciples of the disciples. These holy and learned men instructed the Church in the years of its first growth. Chief among the Fathers of the first six centuries (date is of death), are: the Doctors of the Church, and Saints Clement of Rome (99), Ignatius of Antioch (107), Polycarp (155), Justin (165), Irenaeus (202), Cyprian (258), Dionysius (265), Gregory Thaumaturgus (270), Optatus (372), Martin of Tours (397), Gregory of Nyssa (398), Epiphanius (403), Celestine I (432), Vincent of Lerins (450), and Caesarius of Arles (542). Besides the writings of the Fathers, the truths of Sacred Tradition may be found chiefly in: (a) writings of the Doctors of the Church; (b) decrees of Popes and Church councils; and (c) the liturgy of the Church as found in the Missal and rituals. We call "Doctors of the Church" those ecclesiastical writers, noted for learning and holiness of life, who have by Church authority been proclaimed with that title, and whose feasts have been extended to the whole Western Church. Among the Fathers of the Church, these are honored as Doctors: Saints Hilary (368), Athanasius (373), Ephraem (378), Basil the Great (379), Cyril of Jerusalem (386), Gregory Nazianzen (389), Ambrose (397), John Chrysostom (407), Jerome (420), Augustine (430), Cyril of Alexandria (444), Peter Chrysologus (450), Leo the Great (461), and Gregory the Great (604). Among the outstanding Doctors of the Church of the Middle Ages are: Saints Peter Damian (1072), Anselm of Canterbury (1109), Bernard (1153), Thomas Aquinas (1274), Bonaventure (1274), Albert the Great (1280). Of later Doctors we have: Saints Peter Canisius (1597), John of the Cross (1605), Francis de Sales (1612), Robert Bellarmine (1621), and Alphonsus Liguori (1787).