Several passages have occurred in the foregoing Chapters, which serve to suggest another principle on which some words are now to be said. Theodore's exclusive adoption of the literal, and repudiation of the mystical interpretation of Holy Scripture, leads to the consideration of the latter, as one of the characteristic conditions or principles on which the teaching of the Church has ever proceeded. Thus Christianity developed, as we have incidentally seen, into the form, first, of a Catholic, then of a Papal Church. Now it was Scripture that was made the rule on which this development proceeded in each case, and Scripture moreover interpreted in a mystical sense; and, whereas at first certain texts were inconsistently confined to the letter, and a Millennium was in consequence expected, the very course of events, as time went on, interpreted the prophecies about the Church more truly, and that first in respect of her prerogative as occupying the _orbis terrarum_, next in support of the claims of the See of St. Peter. This is but one specimen of a certain law of Christian teaching, which is this,--a reference to Scripture throughout, and especially in its mystical sense.[339:1] 2. 1. This is a characteristic which will become more and more evident to us, the more we look for it. The divines of the Church are in every age engaged in regulating themselves by Scripture, appealing to Scripture in proof of their conclusions, and exhorting and teaching in the thoughts and language of Scripture. Scripture may be said to be the medium in which the mind of the Church has energized and developed.[339:2] When St. Methodius would enforce the doctrine of vows of celibacy, he refers to the book of Numbers; and if St. Irenæus proclaims the dignity of St. Mary, it is from a comparison of St. Luke's Gospel with Genesis. And thus St. Cyprian, in his Testimonies, rests the prerogatives of martyrdom, as indeed the whole circle of Christian doctrine, on the declaration of certain texts; and, when in his letter to Antonian he seems to allude to Purgatory, he refers to our Lord's words about "the prison" and "paying the last farthing." And if St. Ignatius exhorts to unity, it is from St. Paul; and he quotes St. Luke against the Phantasiasts of his day. We have a first instance of this law in the Epistle of St. Polycarp, and a last in the practical works of St. Alphonso Liguori. St. Cyprian, or St. Ambrose, or St. Bede, or St. Bernard, or St. Carlo, or such popular books as Horstius's _Paradisus Animæ_, are specimens of a rule which is too obvious to need formal proof. It is exemplified in the theological decisions of St. Athanasius in the fourth century, and of St. Thomas in the thirteenth; in the structure of the Canon Law, and in the Bulls and Letters of Popes. It is instanced in the notion so long prevalent in the Church, which philosophers of this day do not allow us to forget, that all truth, all science, must be derived from the inspired volume.