Chapter 1 — Preface to the Roman Catechism
Section 20. Instruction Should Be Accommodated To The Capacity Of The Hearer — Age, capacity, manners and condition must be borne in mind, so that he who instructs may become all things to all men, in order that he may be able to gain all to Christ, prove himself a dutiful minister and steward, and, like a good and faithful servant, be found worthy to be placed by his Lord over many things The priest must not imagine that those committed to his care are all on the same level, so that he can follow one fixed and unvarying method of instruction to lead all in the same way to knowledge and true piety; for some are as new-born infants, others are growing up in Christ, while a few are, so to say, of full maturity. Hence the necessity of considering who they are that have occasion for milk, who for more solid food, and of affording to each such nourishment of doctrine as may give spiritual increase, until we all meet in the unity of faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the age of the fullness of Christ. This the Apostle inculcates for all by his own example when he says that he is a debtor to the Greeks and to the Barbarians, to the wise and to the unwise, thus giving all who are called to this ministry to understand that in announcing the mysteries of faith and the precepts of life, the instruction is to be so accommodated to the capacity and intelligence of the hearers, that, while the minds of the strong are filled with spiritual food, the little ones be not suffered to perish with hunger, asking for bread, while there is none to break it unto them.