Although occasionally fantastic and far-fetched, this symbolism is generally of a profoundly religious significance, and often of extreme poetic beauty. In perpetual canticle of love it finds resemblances of the Divine Object of its devotion throughout all nature. It beholds beyond the shadows of time the eternal verities of the world to come. It is not of the earth earthy, but is entirely supersensual in its character, and employs material forms only as suggestions of the unseen and spiritual. It addresses the inner vision of the soul, and not the mere outer sense. Its merit consists, therefore, not in artistic beauty of execution, but in appositeness of religious significance--a test lying far too deep for the apprehension of the uninitiate. It is perhaps also influenced, as Kugler remarks, in the avoidance of realistic representation, by the fear which pervaded the primitive church of the least approach to idolatry. Great care must be observed, however, in the interpretation of this religious symbolism, not to strain it beyond its capacity or intention. It should be withdrawn from the sphere of theological controversy, too often the battleground of religious rancour and 227 bitterness, and relegated to that of scientific archæology and dispassionate criticism. An allegorizing mind, if it has any theological dogma to maintain, will discover symbolical evidence in its support where it can be detected by no one else.[359] One of the most striking circumstances which impresses an observer in traversing these silent chambers of the dead is the complete avoidance of all images of suffering and woe, or of tragic awfulness, such as abound in sacred art above ground. There are no representations of the sevenfold sorrows of the _Mater Dolorosa_, nor cadaverous Magdalens accompanied by eyeless skulls as a perpetual _memento mori_. There are no pictures of Christ’s agony and bloody sweat, of his cross and passion, his death and burial; nor of flagellations, tortures, and 228 fiery pangs of martyrdom, such as those that harrow the soul in many of the churches and picture-galleries of Rome.[360] Only images of joy and peace abound on every side. These gloomy crypts are a school of Christian love and gentle charity, of ennobling thoughts and elevating impulses. The primitive believers, in the midst of their manifold persecutions, rejoiced even in tribulation. “There is no sign of mourning,” says d’Agincourt, “no token of resentment, no expression of vengeance; all breathes of gentleness, benevolence, and love.” “To look at the Catacombs alone,” says Rochette, “it might be supposed that persecution had no victims, since Christianity has made no allusion to suffering.” There are no symbols of sorrow, no appeals to the morbid sympathies of the soul, nothing that could cause vindictive feelings even toward the persecutors of the church; only sweet pastoral scenes, fruits, flowers, palm branches and laurel crowns,