The doctrine is at once new and yet not new.  It is new in the sense that up to the time of the Vatican Council it had never been actually drawn out of the premises that contained it, and set forth before the faithful in a formal definition.  On the other hand, it is not new, but as old as Christianity, in the sense that it was always contained implicitly in the deposit of faith.  Any body of truth that is living grows, and unfolds and becomes more clearly understood and more thoroughly grasped, as time wears on.  The entire books of Euclid are after all but the outcome of a few axioms and accepted definitions.  These axioms help us to build up certain propositions.  And one proposition, when established, leads to another, till at last we seem to have unearthed statements entirely new and original.  Yet, they are certainly not really new, for had they not been all along contained implicitly in the few initial facts, it is quite clear they could never have been evolved from them. Nemo dat, quod non habet.

Hence Papal Infallibility is not so much a new truth, or an “addition to the Faith,” as some heretics would foolishly try to persuade us, as a clearer expression and a more exact and detailed presentation of what was taught from the beginning.

It is here that the well-known historian, Doellinger, who rejected the definition, proved himself to be not only a proud rebel but also a very poor logician.  Until 1870, he was a practising Catholic, and, therefore, like every other Catholic, he, of course, admitted that the Pope and the Bishops, speaking collectively, were divinely supported and safeguarded from error, when they enunciated to the world any doctrine touching faith or morals.  Yet, when the Pope and the Bishops, assembled at the Vatican, did so speak collectively, and did conjointly issue the decree of Papal Infallibility, he proceeded to eat his own words, refused to abide by their decision, and was deservedly turned out of the Church of God:  being excommunicated by the Archbishop of Munich on the 17th of April, 1871, in virtue of the instructions given by Our Divine Lord Himself, viz.:  “If he will not hear the Church (cast him out, i.e.), let him be to thee as the heathen and publican” (Matt. xviii. 17).  He, and the few misguided men that followed him in his rebellion, and called themselves Old Catholics, had been quite ready to believe that the Pope, with the Bishops, when speaking as one body, were Infallible.  In fact, if they had not believed that, they never could have been Catholics at any time.  But they did not seem to realise the sufficiently obvious fact that, whether they will it or not, and whether they advert to it or not, it is utterly impossible now to deny the Infallibility of the Pope personally and alone, without at the same time denying the Infallibility of the “Pope and the Bishops collectively,” for the simple reason that it is precisely the “Pope and the Bishops collectively” who have solemnly and in open session declared that the Pope enjoys the prerogative of Infallibility in his own individual person.  Since the Vatican Council, one is forced by the strict requirements of sound reason to believe, either that the Pope is Infallible, or else that there is no Infallibility in the Church at all, and that there never had been.