Apologeticae sive Theologiae Fundamentalis, Tomus II (Pars Altera): Demonstratio Catholica

In a twofold way a society can fail, namely with respect to existence and with respect to essence. It can fail with respect to existence, so that it absolutely ceases to be; it can fail with respect to essence, so that it is at least corrupted and consequently becomes unfit for attaining its end. We shall show that the Church of Christ is indefectible both with respect to existence and with respect to essence.

The adversaries of the perpetuity of the Church are not only all the rationalists, but also the Socinians, whose founder Faustus Socinus († 1604)¹ wrote: "That the true face of the Church would exist in perpetuity was nowhere really predicted or absolutely promised … nay, owing to the wickedness of men it could come about that at some time, and that for a very long time too, no visible Church existed."² On the contrary, with nearly all Christians assenting, Catholics have always professed and still profess that the Church will remain until the end of the world. This perpetuity of the Church is indeed proclaimed by Christ, by the apostles, and by the fathers.

1. Christ announces in various ways that the Church will never perish:

a) He equates the Church with the kingdom of God, as we have already shown. But the kingdom of God on earth, according to the messianic prophecies, will stand eternally, until the kingdom of glory in heaven succeeds it.³ Wherefore the angel predicts of Christ, the head of the Church: "He will reign in the house of Jacob forever, and of his kingdom there will be no end."⁴

b) He compares the Church to the field and to the net: to the field, in which the wheat and the tares, evil men and good, grow together until the harvest, i. e., the last judgment;⁵ to the net, into which good and evil fish enter until the consummation of the world.⁶

c) He assigns to the Church the end of saving all men. Since outside the Church there is no salvation, the Church must remain as long as there will be men to be saved. Otherwise Christ would have had to provide men with another way of attaining salvation.

d) He expressly promises the Church perpetuity: "You are Peter, and upon this rock I will build my Church, and the gates of hell shall not prevail against it."⁷ Therefore the Church of Christ, built upon a rocky foundation, will be so firm and so stable that it can never be destroyed by any force, even that of hell.

2. The apostles propose the same perpetuity of the Church both by metaphors and by explicit words. a) They describe the Church under the metaphor of the body and of the bride of Christ. The Church is the body of Christ, and Christ indeed is its head.⁸ But the body of Christ certainly cannot be separated from its head by destruction. Likewise the Church is the bride of Christ. But Christ can never abandon his most beloved bride.⁹ b) Hence in explicit words Paul says of Christ: "For he must reign, until [God] puts all enemies under his feet. But the last enemy, death, will be destroyed."¹⁰ But death will not be destroyed before the end of this world; therefore the kingdom, or the Church, of Christ will last on earth until the end of the world. Elsewhere the apostle of the Gentiles opposes the "immovable kingdom" of the new covenant to the "movable" and "translated" old covenant.¹¹ Finally he declares that the Eucharist will be celebrated in the Church "until Christ comes" to judgment.¹²

3. The fathers inculcate the same doctrine. Ambrose: "The Church has its own times, namely of persecution and of peace. For it seems to wane like the moon, but it does not wane. It can be overshadowed, it cannot wane."¹³ Jerome: "Upon which [rock] the Church, being founded, is shaken by no storm, is overthrown by no whirlwind or winds."¹⁴ Augustine: "No one blots out the constitution of God from heaven, no one blots out the Church of God from the earth."¹⁵ Chrysostom: "It is easier to extinguish the sun than to destroy the Church."¹⁶

Therefore the Church of Christ will exist perpetually until the end of the world. It will exist, moreover, substantially or essentially such as it was instituted by Christ.

Those adversaries who admit that the Church will indeed endure perpetually nevertheless contend that it has been essentially changed or can be changed. The Fraticelli "spirituales", condemned by John XXII, asserted that the gospel had been concealed in the Church until now, indeed wholly extinguished.¹ The Reformers contended that the Church under the supreme pontiffs had been so foully corrupted and collapsed that scarcely its ruins remained.² Following in Protestant footsteps, the Jansenists and the Synod of Pistoia reproached the Church for having "grown old" and obscured nearly all its doctrines.³ To these are added the Modernists, lamenting a spirit of the "curia" hostile to reforms and demanding that the Church conform and adapt itself in all things to the ideas of present-day liberalism.

Catholics, on the contrary, have always held and hold that those things which are of human institution in the Church can indeed be changed according to the various necessities of the times, the essence of the Church instituted by Christ Himself remaining nevertheless unharmed.⁴ This immutability of the Church follows from its perpetuity, its end, its promise, and its infallibility.

1. From the perpetuity of the Church, or its indefectible existence. For the dogma must be applied to the Church: "Let it be, as it is, or let it not be." A Church essentially changed would no longer be the Church of Christ. Hence at the very moment at which the Church would fail with respect to essence, it would already have failed with respect to existence. But, from what has been said, it is indefectible with respect to existence; therefore it is also indefectible with respect to essence.

2. From the end of the Church. The proximate end of the Church consists in this, that through it the work of redemption be rendered perennial, i. e. that the Christian religion be preserved and administered; the remote end of the Church, however, consists in this, that in it and through it men may be saved, i. e. may attain eternal life. It is evident, moreover, that both the one and the other end would be impossible of attainment if the Church were essentially corrupted.

3. From the promise of the Church. For Christ promised the Church so great a stability that the gates of hell shall not prevail against it.⁵ But the gates of hell would altogether prevail against the Church if they corrupted it essentially. Moreover, Christ promised that He would be with the Church even to the end of the world: "Behold, I am with you all days even to the consummation of the world."⁶ But the assistance of Christ must most efficaciously prevent the Church from failing in its essence.

4. From the infallibility of the Church. In the second section of the Catholic demonstration we shall show that Christ instituted in His Church an infallible magisterium, which neither errs nor can err concerning the deposit of revelation, i. e. concerning all those things which are of the essence of the Christian religion. But since the Church adheres, and must necessarily adhere, to this magisterium, it is itself rendered infallible. Whence it cannot be changed or corrupted.