It is not a doctrinal or polemical essay, its purport and scope being purely archaeological. My object has been to combine under one comprehensive and systematic scheme, in the full and true meaning of the word archaeology, and for the purpose of mutual illustration, the varied information derived from the silent architecture and material remains of ecclesiastical antiquity, with the written records of the manners and customs of those who were their authors, and to exhibit the religious and social condition of our forefathers as if they lived again. To discuss one without the other of these essential elements of information is to produce an incomplete and unsatisfactory view of a subject which must, when an author writes in the interest of no party, embrace both. The history of dogma is thus studied by the aid of direct and incorruptible evidence, whilst the changes and diversity of ritual and discipline, the forms of popular superstition, and lingering tradition, lend their visible or oral testimony to the facts of the past for all who would understand the spirit of the Church, the shadow itself being but a deepened light.<br><br>The subjects treated will be found to range themselves under the two great classes indicated above.<br><br>I. The Arts. - 1. Architecture, religious buildings, the crypt, the catacomb, chapels, basilicas, baptisteries, churches and their various divisions, minsters, altars, tombs. 2. Sculpture, statues, wood-carving, bas-reliefs, diptychs, sacred vessels, effigies, gems. 3. Painting, mural fresco, and diaper, stained glass, mosaics, iconography, symbolism, emblems, colour. 4. Engraving, inscriptions, brasses, slabs. 5. Furniture and plate, vestments, veils, hangings, apparel of the altar, ecclesiastical ornaments of ministers, and divine service.