Article — Prümmer, Manuale Theologiae Moralis
Article I. On paganism and Judaism
510. Proposition 1. Negative or material infidelity is not a sin.
The reason is that what is caused by invincible ignorance is not a sin. But negative infidelity arises from invincible ignorance; for if an unbeliever knows that he is in error and nevertheless does not embrace faith, he already labors under positive infidelity and not merely negative infidelity. Hence proposition (68) of Baius was condemned: "Purely negative infidelity in those to whom Christ has not been preached is a sin."10
Proposition 2. Positive or formal infidelity is a very grave sin.
The reason is a) because it is a grave contempt of the authority of God revealing; b) because it rejects a means altogether necessary for salvation, such as faith is; c) because on account of this infidelity man will be condemned in the other life, according to that saying: "But he who does not believe shall be condemned."11
10 Denz. n. 1068. Cf. S. theol. 2, 2, q. 10, a. 1.
11 Mark 16, 16.
511. Proposition 3. a) Pagans and Jews, although they are not to be impelled violently to embrace the Catholic faith, can nevertheless be compelled not to impede Catholic worship or afflict it with reproaches;
b) by Christian princes the rites and worship of unbelievers can sometimes, for a grave cause, be tolerated.13
a) As to the first part of this proposition St. Thomas writes:12 "There are some unbelievers who have never received the faith, such as gentiles and Jews; and such are in no way to be compelled to the faith so that they themselves believe, because to believe belongs to the will. Yet they are to be compelled by the faithful, if there is the ability, not to impede the faith either by blasphemies or by evil persuasions or even by open persecutions. And on account of this the faithful of Christ frequently wage war against unbelievers, not indeed that they may force them to believe, because even if they had conquered them and had them captive, they would leave it to their liberty whether they wished to believe; but for this reason, that they may compel them not to impede the faith of Christ."
b) But as to the other part of the proposition the same Holy Doctor writes:14 "Human rule is derived from divine rule, and ought to imitate it. But God, although He is omnipotent and supremely good, nevertheless permits certain evils to be done in the universe, which He could prohibit, lest by those evils being removed greater goods should be taken away or even worse evils should follow. Thus, therefore, in human rule those who preside rightly tolerate certain evils, lest certain goods be impeded, or even lest worse evils be incurred; as Augustine says: 'Take away prostitutes from human affairs, and you will disturb all things by lusts.' Thus, therefore, although unbelievers sin in their rites, they can be tolerated either on account of some good which comes from them, or on account of some evil which is avoided." - But a grave cause is required in order that a Christian prince can licitly sometimes tolerate the public worship of unbelievers. For the so-called unlimited "liberty of cults" has several times been proscribed by the Supreme Pontiffs, because the same liberty is not to be granted to error and truth. Thus, e.g., Pius IX in the Syllabus condemned the following propositions:15 "In this our age it is no longer expedient that the Catholic religion be held as the only religion of the state, all other cults whatsoever being excluded"; "Hence it has laudably been provided by law in certain regions of Catholic name that it be permitted to men immigrating there to have the public exercise of each one's own cult"; "Indeed it is false that civil liberty of every cult, and likewise full power attributed to all of manifesting openly and publicly any opinions and thoughts whatsoever, conduces to more easily corrupting the morals and minds of peoples and to propagating the pest of indifferentism."
From this doctrine of Pius IX the Catholic Church can by no means be accused of so-called "intolerance."
For even if the Church cannot admit dogmatic tolerance, i.e. permit errors in faith to be spread, nevertheless she exercises civil tolerance, i.e. she not only tolerates non-Catholics, but also pursues them with true Christian love. Wherefore, e.g., she has never persecuted the Jews, as modern Antisemitism does.
13 Leo XIII teaches the same, Encyclical "Immortale Dei," November 1, 1885.
12 S. theol. 2, 2, q. 10, a. 8.
14 S. theol. 2, 2, q. 10, a. 11.