His warning to the Galatians a warning to all.
[24.] But, possibly, this warning was intended for the Galatians only. Be it so; then those other exhortations which follow in the same Epistle were intended for the Galatians only, such as, |If we live in the Spirit, let us also walk in the Spirit; let us not be desirous of vain glory, provoking one another, envying one another,| etc.; which alternative if it be absurd, and the injunctions were meant equally for all, then it follows, that as these injunctions which relate to morals, so those warnings which relate to faith are meant equally for all; and just as it is unlawful for all to provoke one another, or to envy one another, so, likewise, it is unlawful for all to receive any other Gospel than that which the Catholic Church preaches everywhere.
[25.] Or perhaps the anathema pronounced on any one who should preach another Gospel than that which had been preached was meant for those times, not for the present. Then, also, the exhortation, |Walk in the Spirit and ye shall not fulfil the lust of the flesh,| was meant for those times, not for the present. But if it be both impious and pernicious to believe this, then it follows necessarily, that as these injunctions are to be observed by all ages, so those warnings also which forbid alteration of the faith are warnings intended for all ages. To preach any doctrine therefore to Catholic Christians other than what they have received never was lawful, never is lawful, never will be lawful: and to anathematize those who preach anything other than what has once been received, always was a duty, always is a duty, always will be a duty.
[26.] Which being the case, is there any one either so audacious as to preach any other doctrine than that which the Church preaches, or so inconstant as to receive any other doctrine than that which he has received from the Church? That elect vessel, that teacher of the Gentiles, that trumpet of the apostles, that preacher whose commission was to the whole earth, that man who was caught up to heaven, cries and cries again in his Epistles to all, always, in all places, |If any man preach any new doctrine, let him be accursed.| On the other hand, an ephemeral, moribund set of frogs, fleas, and flies, such as the Pelagians, call out in opposition, and that to Catholics, |Take our word, follow our lead, accept our exposition, condemn what you used to hold, hold what you used to condemn, cast aside the ancient faith, the institutes of your fathers, the trusts left for you by your ancestors and receive instead, -- what? I tremble to utter it: for it is so full of arrogance and self-conceit, that it seems to me that not only to affirm it, but even to refute it, cannot be done without guilt in some sort.