We have arrived at length at the seventh and last test, which was laid down when we started, for distinguishing the true development of an idea from its corruptions and perversions: it is this. A corruption, if vigorous, is of brief duration, runs itself out quickly, and ends in death; on the other hand, if it lasts, it fails in vigour and passes into a decay. This general law gives us additional assistance in determining the character of the developments of Christianity commonly called Catholic.
When we consider the succession of ages during which the Catholic system has endured, the severity of the trials it has undergone, the sudden and wonderful changes without and within which have befallen it, the incessant mental activity and the intellectual gifts of its maintainers, the enthusiasm which it has kindled, the fury of the controversies which have been carried on among its professors, the impetuosity of the assaults made upon it, the ever-increasing responsibilities to which it has been committed by the continuous development of its dogmas, it is quite inconceivable that it should not have been broken up and lost, were it a corruption of Christianity. Yet it is still living, if there be a living religion or philosophy in the world; vigorous, energetic, persuasive, progressive; vires acquirit eundo; it grows and is not overgrown; it spreads out, yet is not enfeebled; it is ever germinating, yet ever consistent with itself. Corruptions indeed are to be found which sleep and are suspended; and these, as I have said, are usually called "decays:" such is not the ease with Catholicity; it does not sleep, it is not stationary even now; and that its long series of developments should be corruptions would be an instance of sustained error, so novel, so unaccountable, so preternatural, as to be little short of a miracle, and to rival those manifestations of Divine Power which constitute the evidence of Christianity. We sometimes view with surprise and awe the degree of pain and disarrangement which the human frame can undergo without succumbing; yet at length there comes an end. Fevers have their crisis, fatal or favourable; but this corruption of a thousand years, if corruption it be, has ever been growing nearer death, yet never reaching it, and has been strengthened, not debilitated, by its excesses.