Second, the instrumental causes, which are the holy men of God.
Second, the instrumental causes, which are the holy men of God.
§ 18. The instrumental causes of Holy Scripture were “holy men of God” (2 Pet. 1:21), that is, men whom God immediately and especially called and chose for this purpose: to put down in writing the divine revelations. These were the prophets in the Old Testament and the evangelists and apostles in the New. Consequently, we correctly call them the amanuenses of God, the hands of Christ, the scribes or notaries of the Holy Spirit, since they neither spoke nor wrote by human will or their own will, but rather were 
—driven, led, impelled, inspired, and controlled by the Holy Spirit. They did not write as men but as “men of God,” that is, they wrote as God’s servants and as the unique instruments of the Holy Spirit. Therefore when we call a canonical book a “book of Moses,” “the Psalter of David,” “an epistle of Paul,” we are doing this merely with regard to their ministry, not with regard to its principal cause.
For this reason, Augustine speaks as follows about the canonical books of the Old Testament: “For them (the Israelites), these were philosophers, wise men, theologians, prophets, professors of uprightness and piety. Whoever lived and learned according to them learned and lived not according to men but according to God, who spoke through them. These mouths did not pour out human but divine oracles” (De civ. Dei, bk. 18, c. 41). On the canonical books of the New Testament, Augustine explains: “Whatever Christ wanted us to know about His words and actions, He commanded them (the evangelists and apostles) to write as if with His hands” (De cons. Evang., bk. 1, c. 35).