Fig. 5.—Section of the Basilica of Maxentius or Constantine (Temple of Peace).
In view of the above it might be questioned whether it is safe to speak of a normal form of the basilica, but when we consider the vast number of basilicas that have perished compared to the few that have survived, and the fact that the origins and traditions of the building show it to have been, as Vitruvius describes it, essentially a columned structure, there is ample justification for the view expressed earlier in this article. There can be little doubt that the earlier basilicas, and the majority of basilicas taken as a whole, had a central space with galleries, generally in two stories, round it, and some arrangement for clerestory lighting. Later basilicas might vary in architectural scheme, while affording the same sort of accommodation as the older ones.
The relation of the civil basilica of the Romans to the Christian church has been extensively discussed, and the reader will find the controversy ably summarized in Kraus's Geschichte der christlichen Kunst, bk. 5. There is nothing remarkable in the fact that a large church was called a basilica, for the term was applied, as we have seen, to structures of many kinds, and we even find "basilica" used for the meeting-place of a pagan religious association (Röm. Mitt. 1891, p. 109). The similarity in some respects of the early Christian churches to the normal form of the columned basilica is so striking, that we can understand how the theory was once held that Christian churches were the actual civil basilicas turned over from secular to religious uses. There is no evidence for this in the case of public basilicas, and it stands to reason that the demands on these for secular purposes would remain the same whether Christianity were the religion of the empire or not. Moreover, though there are one or two civil basilicas that resemble churches, the latter differ in some most important respects from the form of the basilica that we have recognized as normal. The early Christian basilicas, at any rate in the west, had very seldom, if ever, galleries over the side aisles, and their interior is always dominated by the semi-dome of an apse that terminates the central nave, whereas, with the doubtful exception of Silchester (Archaeologia, liii. 549), there is no instance known of a vaulted apse in a columned civil basilica of the normal kind.
Fig. 6.—Plan of Basilica adjoining the Forum of the Roman city of Timgad, in North Africa.
(From Gsell's Monuments antiques de l'Algerie, by permission of A. Fontemoing.)
When buildings were first expressly erected for Christian worship, in the 3rd or perhaps already in the 2nd century A.D. (Leclercq, Manuel, ch. iii. "Les édifices chrétiens avant la paix de l'église"), they probably took the form of an oblong interior
terminated by an apse. After the time of Constantine, when the numbers of the faithful were enormously increased, side aisles were added, and in this way the structure came to assume an appearance similar to that of the civil basilica. A striking confirmation of this view has recently come to light at S. Saba on the Aventine at Rome, where a small and very early church, without aisles, has been discovered beneath the floor of the present basilica.
There are, on the other hand, instances in which private basilicas in palaces and mansions were handed over to the Christians for sacred uses. We know that to have been the case with the basilicas of S. Croce in Gerusalemme and S. Maria Maggiore at Rome, which originated in the halls of the Sessorian and Liberian palaces respectively, granted by Constantine to the Christians. We may adduce also as evidence of the same practice a passage in bk. x. ch. 71 of the theological romance known as The Recognitions of Clement, probably dating from the early half of the 3rd century, in which we are told that Theophilus of Antioch, on his conversion by St Peter, made over "the basilica of his house" for a church. But however this may have been, with, perhaps, the single exception of S. Croce, the existing Christian basilicas were erected from the ground for their sacred purpose. At Rome the columns, friezes and other materials of the desecrated temples and public buildings furnished abundant materials for their construction. The decadence of art is plainly shown by the absence of rudimentary architectural knowledge in these reconstructions. Not only are columns of various heights and diameters made to do duty in the same colonnade, but even different orders stand side by side (e.g. Ionic, Corinthian and Composite at S. Maria in Trastevere); while pilasters assume a horizontal position and serve as entablatures, as at S. Lorenzo fuori le Mura. There being no such quarry of ready-worked materials at Ravenna, the noble basilicas of that city are free from these defects, and exhibit greater unity of design and harmony of proportions.
