Laymen Forbidden to Teach/Dispute (Roman Catholicism and Eastern Orthodoxy)

Roman Catholicism.

Pope Alexander IV (c. 1185/99-1261 A.D.) [The Catholic Encyclopedia]:

By a decree of Alexander IV (1254-1261) inserted in “Sextus Decretalium”, Lib. V, c. ii, and still in force, all laymen are forbidden, under threat of excommunication, to dispute publicly or privately with heretics on the Catholic Faith. The text reads: “Inhibemus quoque, ne cuiquam laicæ personæ liceat publice vel privatim de fide catholicâ disputare. Qui vero contra fecerit, excommunicationis laqueo innodetur.” (We furthermore forbid any lay person to engage in dispute, either private or public, concerning the Catholic Faith. Whosoever shall act contrary to this decree, let him be bound in the fetters of excommunication.) …when there is a question of dogmatic or moral theology, every intelligent layman will concede the propriety of leaving the exposition and defence of it to the clergy. 

(James F. Loughlin, S.T.D., “Discussions, Religious;” In: The Catholic Encyclopedia: Volume V: Special Edition, [New York: The Encyclopedia Press, Inc., 1913], p. 34. Ecclesiastical approbation: Nihil Obstat, May 1, 1909, Remy Lafort, Censor. Imprimatur, John M. Farley, Archbishop of New York.)

Eastern Orthodoxy.

Quinisext Council (681 A.D.), Canon 64:

That a layman must not publicly make a speech or teach, thus investing himself with the dignity of a teacher, but, instead, must submit to the ordinance handed down by the Lord, and to open his ear wide to them who have received the grace of teaching ability, and to be taught by them the divine facts thoroughly. For in the one Church God created different members, according to the utterance of the Apostle, in interpreting which St. Gregory the Theologian clearly presents the right procedure in these matters by saying: “Let us have respect for this procedure, brethren, and let us observe it. First, let one man be a listener, as the hearing recipient; another, the tongue; another, a hand; another, something else; let one man teach, and let another man learn; and after short periods, as touching one who learns in a state of obedience, and one who leads the chorus in hilarity, and one who renders service in cheerfulness and willingness, let us not all be a tongue, heeding the most apt saying: “Let us not all be Apostles; let us not all be Prophets; let us not all be Interpreters” (1 Cor. 12:29), and after somewhat: “Why are you making out that you are a shepherd, when you are a sheep? Why are you becoming a head, when you happen to be a foot? Why are you attempting to be a general, when you are placed in the ranks of (ordinary) soldiers? And from another quarter Wisdom bids: ‘Be not hasty in words; vie not with a rich man when thou art indigent’ (Prov. 23:4); nor seek to be wiser than the wise. If anyone be caught disobeying the present Canon, let him be excommunicated for forty days.

(Quinisext Council (681 A.D.), Canon 64; In: The Rudder (Pedalion) of the Metaphorical Ship of the One Holy Catholic and Apostolic Church of the Orthodox Christians, or All the Sacred and Divine Canons, trans. D. Cummings, [Chicago: The Orthodox Christian Educational Society, 1957], Canon LXIV, p. 363).

καὶ αὐτός ἐστιν πρὸ πάντων καὶ τὰ πάντα ἐν αὐτῷ συνέστηκεν ~ Soli Deo Gloria