IT is the general pretext of heretics that they are but serving and protecting Christianity by their innovations; and it is their charge against what by this time we may surely call the Catholic Church, that her successive definitions of doctrine have but overlaid and obscured it. That is, they assume, what we have no wish to deny, that a true development is that which is conservative of its original, and a corruption is that which tends to its destruction. This has already been set down as a Sixth Test, discriminative of a development from a corruption, and must now be applied to the Catholic doctrines; though this Essay has so far exceeded its proposed limits, that both reader and writer may well be weary, and may content themselves with a brief consideration of the portions of the subject which remain.

It has been observed already that a strict correspondence between the various members of a development, and those of the doctrine from which it is derived, is more than we have any right to expect. The bodily structure of a grown man is not merely that of a magnified boy; he differs from what he was in his make and proportions; still manhood is the perfection of boyhood, adding something of its own, yet keeping what it finds. "Ut nihil novum," says Vincentius, "proferatur in senibus, quod non in pueris jam antea latitaverit." This character of addition,—that is, of a change which is in one sense real and perceptible, yet without loss or reversal of what was before, but, on the contrary, protective and confirmative of it,—in many respects and in a special way belongs to Christianity.