You are thinking of what many RCs seem to see as the old days, when Rome could use the sword of men against challengers, and her members were much dissuaded from engaging in interpretation of their magisterium, and laymen were overall forbidden to debate such. But who were sometimes employed in reporting them*.
Now the lay RC apologists can and do engage in the messy street level work of defending the object of their devotion, the RCC, though that often shows how differently they can interpret their magisterium, and how much is insufficiently addressed by it. And how it can change its laws.
"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. — Pope Alexander IV (1254-1261) in “Sextus Decretalium” (http://archive.org/details/OEXV7_2), and still in force at the time (1913) when the the Catholic Encyclopedia was written, which adds,
“This law, like all penal laws, must be very narrowly construed. The terms Catholic Faith and dispute have a technical signification. The former term refers to questions purely theological; the latter to disputations more or less formal, and engrossing the attention of the public. But 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.” [who themselves needed due authorization]. — http://www.newadvent.org/cathen/05034a.htm
Quinisext Ecumenical Council, 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.
“the Church forbids the faithful to communicate with those unbelievers who have forsaken the faith they once received, either by corrupting the faith, as heretics, or by entirely renouncing the faith, as apostates, because the Church pronounces sentence of excommunication on both.” St. Thomas Aquinas, Summa Theologica
Do not converse with heretics even for the sake of defending the faith, for fear lest their words instil their poison in your mind. Bl. Isaias Boner of Krakow (Polish, Augustinian priest, theologian, professor of Scripture, d. 1471)
(These are now considered defunct http://turretinfan.blogspot.com/2009/12/lay-roman-catholic-and-eastern-orthodox.html)
Is it permitted for Christians to be present at, or to take part in, conventions, gatherings, meetings, or societies of non-Catholics which aim to associate together under a single agreement everyone who, in any way, lays claim to the name of Christian? In the negative! - (Pope Pius XI, Mortalium Animos)
No one shall pray in common with heretics and schismatics" - Council of Laodicea.
*The intolerance of the Church toward error, the natural position of one who is the custodian of truth, her only reasonable attitude makes her forbid her children to read or to listen to heretical controversy, or to endeavor to discover religious truths by examining both sides of the question." “The reason of this stand of his is that, for him, there can be no two sides to a question which for him is settled; for him, there is no seeking after the truth: he possesses it in its fulness, as far as God and religion are concerned. — (John H. Stapleton, Explanation of Catholic Morals, Chapter xxiii. the consistent believer (1904); Nihil Obstat. Remy Lafort, Censor Librorum. Imprimatur, John M. Farley, Archbishop of New York )
*Canon 1. We appoint, therefore, that the archbishops and bishops shall swear in one priest, and two or three laymen of good report, or more if they think fit, in every parish, both in and out of cities, who shall diligently, faithfully, and frequently seek out the heretics in those parishes, by searching all houses and subterranean chambers which lie under suspicion. And looking out for appendages or outbuildings, in the roofs themselves, or any other kind of hiding places, all which we direct to be destroyed.
Canon 6. Directs that the house in which any heretic shall be found shall be destroyed. (Source: Heresy and Authority in Medieval Europe, Edited with an introduction by Edward Peters, Scolar Press, London, copyright 1980 by Edward Peters, ISBN 0-85967-621-8, pp. 194-195, citing S. R. Maitland, Facts and Documents [illustrative of the history, doctrine and rites, of the ancient Albigenses & Waldenses], London, Rivington, 1832, pp. 192-194.) http://www.hol.com/~mikesch/banned.htm; http://www.justforcatholics.org/a79.htm
From the *church which never changes*, eh?