The transformation may be followed stage by stage in both its moral and material aspect. There is not a ruin of ancient Rome that does not bear evidence of the great change. Many institutions and customs still flourishing in our days are of classical origin, and were adopted, or tolerated, because they were not in opposition to Christian principles. Beginning with the material side of the question, the first monument to which I have to refer is the Arch of Constantine, raised in 315 at the foot of the Palatine, where the Via Triumphalis diverges from the Sacra Via. The importance of this arch, from the point of view of the question treated in this chapter, rests not on its sculptured panels and medallions,--spoils taken at random from older structures, from which the arch has received the nickname of Æsop's crow (_la cornacchia di Esopo_),--but on the inscription engraved on each side of the attic. "The S. P. Q. R. have dedicated this triumphal arch to Constantine, because _instinctu divinitatis_ (by the will of God), and by his own virtue, etc., he has liberated the country from the tyrant [Maxentius] and his faction." The opinion long prevailed among archæologists that the words _instinctu divinitatis_ were not original, but added after Constantine's conversion. Cardinal Mai thought that the original formula was _diis faventibus_, "by the help of the gods," while Henzen suggested _nutu Iovis optimi maximi_, "by the will of Jupiter." Cavedoni was the first to declare that the inscription had never been altered, and that the two memorable words--the first proclaiming officially the name of the true God in the face of imperial Rome--belonged to the original text, sanctioned by the Senate. The controversy was settled in 1863, when Napoleon III. obtained from the Pope the permission to make a plaster cast of the arch. With the help of the scaffolding, the scholars of the time examined the inscription, the shape of each letter, the holes of the bolts by which the gilt-bronze letters were fastened, the joints of the marble blocks, the color and quality of the marble, and decided unanimously that the inscription had never been tampered with, and that none of its letters had been changed. [Illustration: ARCH OF CONSTANTINE]