It is proved by all the historical monuments and especially by the writings of Luther and Calvin that, prior to the anathema pronounced against them at the Council of Trent, the leaders of the Reformation had proclaimed and repeated that the Roman Church was "the Babylon of the Apocalypse, the synagogue of Satan, the society of Antichrist "; that they must therefore depart from it and that they did so in order to re-enter the way of salvation. Thus the schism was well consummated by them before it was solemnly established by the authority which they rejected and transformed by that authority into a just penal sanction.
As schism in its definition and full sense is the practical denial of ecclesiastical unity, the explanation of the former requires a clear definition of the latter, and to prove the necessity of the latter is to establish the intrinsic malice of the former.
Schism (from the Greek schisma , rent, division) is, in the language of theology and canon law, the rupture of ecclesiastical union and unity, i.e.
either the act by which one of the faithful severs as far as in him lies the ties which bind him to the social organization of the Church and make him a member of the mystical body of Christ, or the state of dissociation or separation which is the result of that act. that there be no schisms among you; but that you be perfect in the same mind, and in the same judgment" (ibid., i, 10). Jerome, "there is this difference, that heresy perverts dogma, while schism, by rebellion against the bishop, separates from the Church. Augustine: "By false doctrines concerning God heretics wound faith, by iniquitous dissensions schismatics deviate from fraternal charity, although they believe what we believe " (De fide et symbolo, ix). Jerome remarks, practically and historically, heresy and schism nearly always go hand in hand; schism leads almost invariably to denial of the papal primacy.
Have we not one and the same God, one and the same Christ? Ignatius insists no less forcibly on the necessity of unity and the danger of schism.