Given the existence of a Catholic state, there arises the question of the correct attitude of the civil authorities to minority religions. Writing in the September 1950 issue of the American Ecclesiastical Review, Mgr. George W. Shea explained:
Before another word is said on this subject, let it be noted at once that no Catholic holds or may hold that the state would be called upon to impose the Catholic faith on dissident citizens. Reverence for the invididual conscience forbids this, and the very nature of religion and of the act of faith. If these be not voluntary they are nought.
It is a fundamental principle of Catholic theology that no one must ever be forced to act against his conscience either in public or private (unfortunately this principle has not always been respected in the history of the Church). It is equally true that no one must be prevented from acting in accordance with his conscience in private (providing that no breach of the natural law is involved). Thus, for the most part, a policy of toleration towards the Jews was followed in the papal states. Jews were allowed to hold ceremonies in public or to proselytize among Catholics. (see the article “Toleration” in the Catholic Encyclopedia). This last point brings us to the crucial issue in this pamplet, i.e., that it has been the consistent teaching of the Popes that a Catholic state has the right to restrict the public expression of heresy. Thus, in a Catholic state, members of a Protestant sect could not be compelled to assist at Mass, but they could be prevented from holding outdoor services, putting up notices outside their places of worship designating them as such, or advertising their services. This was the case in Malta when I served there with the British Army. Protestant ministers were not so much as allowed to wear a Roman collar in the street– a ruling which even applied to military chaplains. Similarly, in a Catholic state, a Protestant could not be compelled to profess belief in transubstantiation but could be prevented from attacking the doctrine in public, either by the written or the spoken word. Thus Father Francis J. Connell, C.SS.R., explained in 1949:
Hence, just as the state can prohibit people from preaching the doctrine of free love, so it can prohibit them from preaching, to the detriment of Catholic citizens, the doctrine that Christ is not present in the Holy Eucharist.
Father Connell also pointed out that, although Catholic states had the right to repress heresy, this was not a duty. Where a large minority religion existed within a Catholic state more harm than good might result from attempting to limit the public expression of heresy. In such cases heresy would be tolerated as the lesser of two evils, e.g., to avoid the type of civil war which occurred in attempting to suppress Protestantism in France. However, the distinction between what is tolerated and what is a right is both obvious and important.
Archbishop Lefebvre and Religious Liberty, p. 4-5.