But we must not pursue this subject any further. We have said enough, we think, to establish the competency of these paintings as witnesses to the ancient faith, and we will now proceed to question them concerning one or two principal mysteries of the faith—those that are called its mysteries _par excellence_: its sacraments. We do not doubt that, if duly interrogated, they will have some evidence to give. We say, if duly interrogated, because it is the characteristic of ancient Christian art to be eminently symbolical; it suggested rather than declared religious doctrines and ideas, and it suggested them by means of artistic symbols or historical types, which must be inquired into and meditated upon before they can be made fully to express their meaning. This is of the very essence of a symbol: that it should partly veil and partly manifest the truth. It does not manifest the truth with the fulness and accuracy of a written historical description, or it would cease to be a symbol; on the other hand, it must not be so obscure as to demand a sibyl for its interpretation; it must have a tendency to produce in the mind of the beholder some leading feature of the object it is intended to represent. And where should symbols of this kind be more abundantly found for the Christian preacher or artist than in the histories of the Old Testament? Ancient Christian art, says Lord Lindsay, “veiled the faith and hope of the church under the parallel and typical events of the patriarchal and the Jewish dispensations.” We need not remind our readers that the principle of this method of interpreting Holy Scripture has express apostolic sanction; but few who have not studied the subject closely will have any adequate idea of the extent to which it was followed in the ancient church. We will give a single example, selected because it closely concerns the first mystery of which we propose to speak—the Sacrament of Baptism.