Mosaic, which in classic times was used only for the decoration of floors, was employed in Christian art in the more honourable task of adorning the walls of the stately basilicas and churches. This intractable material was not adapted for the delineation of objects requiring delicacy of expression, but was admirably suited for representing strongly pronounced types and solemn figures of Christ and the saints, analogous to those in the stained-glass windows of gothic cathedrals and minsters. Hence the mosaics, and gradually all Byzantine art, stiffened into an expression of severity and gloom, filling the mind of the beholder with solemnity and awe.[355] This character is still strikingly seen in the art of the Greek church, especially in Russia, where there is an intense and superstitious 224 reverence for pictures, known nowhere else. Many of the churches are completely covered with paintings, which are valued, not for their execution, for they are often hideously ugly, but as a sort of talismans on account of their supposed religious sanctity.[356] Thus art, which is the daughter of paganism, relapsing into the service of superstition, has corrupted, and often paganized, Christianity, as Solomon’s heathen wives turned his heart from the worship of the true God to the practice of idolatry. Lecky attributes this degradation of style to the latent Manicheism of the dark ages, to the monkish fear of beauty as a deadly temptation, and to the terrible pictures of Dante, which opened up such an abyss of horrors to the imagination. But by means of this mediæval art, imperfect, and even grotesque as it often was, would be brought vividly before the minds of the people of a rude and barbarous age an intense conception of the scenes of Christ’s passion, and a realistic sense of the punishment of the lost. It will be convenient to treat the art of the Catacombs under the two heads of symbolical and biblical paintings, and to discuss separately the gilt glasses and other objects of interest found in these crypts. De Rossi divides the subject into symbolical, allegorical, biblical, and liturgical paintings; but some of these divisions, as for instance, the last, assumes the whole question of the purport and interpretation of these pictures. [325] M. Didron’s _Iconographie Chrétienne_ is a valuable contribution on this important subject. [326] In the beautiful figure of Pressensé, all art is an Æolian harp, shivering with the breezes that pass over it. [327] _Handbuch der Kunstgeschichte_, p. xii.