Tradition becomes known to us: (a) through the teaching of the Church expressed by her solemn or ordinary magisterium; (b) through the writings of the Fathers of the Church; (c) through the practice of the Church expressed in her universal customs and laws; (d) through the worship of the Church expressed in her universal forms of prayer and liturgical observance. 9. Decisions.--In addition to divine tradition just spoken of, Moral Theology uses: (a) Apostolic tradition, which comes down from the Apostles, but whose subject-matter is not a teaching revealed to them, but an ordinance which they themselves made as rulers of the Church (e.g., the law that Sunday be sanctified as the Lord’s day); (b) ecclesiastical tradition, which contains regulations made by the authorities in the Church and handed down to succeeding times (e.g., the introduction of certain days of feast or fast). 10. Authority of Doctors and Theologians.--(a) St. Thomas Aquinas has been recognized by the Church as her highest theological authority, and the Code of Canon Law (Canons 589, Sec. 1, and 1366, Sec. 2) orders that in all seminaries and religious houses of study the courses of theology shall be made according to his method, teaching and principles. (b) When the theologians agree with unanimity that a certain doctrine pertaining to faith or morals is divinely revealed, it would be next to heresy to hold the opposite; if they agree only that it is certain, it would be rash to contradict them, unless new and serious objections unknown to them can be offered; if they are divided between schools and systems (even though great claims for opinions are made by their partisans), it is lawful for competent theologians to use their own judgment and decide for the side that seems to have the better arguments in its favor. 11. Reason.--The uses of natural reason in Moral Theology are: (a) it demonstrates certain preambles to the teachings of Moral Theology, such as the existence of God, His omniscience and veracity; (b) it corroborates from philosophy many of the revealed teachings, viz., that man’s end is not in things finite, that he has duties to God, to society, to himself, etc.; (e) it affords analogies in the natural order by which we may illustrate the end and duties of man in the supernatural order; (d) it supplies the means by which the teachings on morals may be developed into the conclusions that are contained in them, by which those teachings may be defended against the fallacious objections of adversaries, and by which the whole may be arranged scientifically into a body of doctrine.