I have been engaged in drawing out the positive and direct argument in proof of the intimate connexion, or rather oneness, with primitive Apostolic teaching, of the body of doctrine known at this day by the name of Catholic, and professed substantially both by Eastern and Western Christendom. That faith is undeniably the historical continuation of the religious system, which bore the name of Catholic in the eighteenth century, in the seventeenth, in the sixteenth, and so back in every preceding century, till we arrive at the first;--undeniably the successor, the representative, the heir of the religion of Cyprian, Basil, Ambrose and Augustine. The only question that can be raised is whether the said Catholic faith, as now held, is logically, as well as historically, the representative of the ancient faith. This then is the subject, to which I have as yet addressed myself, and I have maintained that modern Catholicism is nothing else but simply the legitimate growth and complement, that is, the natural and necessary development, of the doctrine of the early church, and that its divine authority is included in the divinity of Christianity. 2. So far I have gone, but an important objection presents itself for distinct consideration. It may be said in answer to me that it is not enough that a certain large system of doctrine, such as that which goes by the name of Catholic, should admit of being referred to beliefs, opinions, and usages which prevailed among the first Christians, in order to my having a logical right to include a reception of the later teaching in the reception of the earlier; that an intellectual development may be in one sense natural, and yet untrue to its original, as diseases come of nature, yet are the destruction, or rather the negation of health; that the causes which stimulate the growth of ideas may also disturb and deform them; and that Christianity might indeed have been intended by its Divine Author for a wide expansion of the ideas proper to it, and yet this great benefit hindered by the evil birth of cognate errors which acted as its counterfeit; in a word, that what I have called developments in the Roman Church are nothing more or less than what used to be called her corruptions; and that new names do not destroy old grievances. This is what may be said, and I acknowledge its force: it becomes necessary in consequence to assign certain characteristics of faithful developments, which none but faithful developments have, and the presence of which serves as a test to discriminate between them and corruptions. This I at once proceed to do, and I shall begin by determining what a corruption is, and why it cannot rightly be called, and how it differs from, a development. 3.