Nevertheless, the testimony of the Catacombs gives evidence that art was not, as has been frequently asserted, entirely abjured by the primitive Christians on account of its idolatrous employment by the pagans. They rather adopted and purified it for Christian purposes, 204 just as they did the diverse elements of ancient civilization. It was not till increasing wealth and the growing corruptions of the church led to the more lavish employment of art and its perversion to superstitious uses that it called forth the condemnation of the Fathers of the early centuries. The art of any people is an outgrowth and efflorescence of an internal living principle: and as is the tree so is its fruit. An adequate representation of its art being given, we may estimate, at least proximately, the moral condition of any age or community. It is the perennial expression of the phenomena of humanity. The iconography of the early centuries of Christianity is, therefore, a pictorial history of its development and of the successive changes it has undergone.[325] The corruptions of doctrine, the rise of dogmas, the strifes of heresiarchs and schismatics, are all reflected therein.[326] The frescoes of the Catacombs are illustrations, inestimable in value, of the pure and lofty character of that primitive Christian life of which they were the offspring. They were the exponent of a mighty spiritual force, “seeking,” as Kugler remarks, “to typify in the earthly and perishing the abiding and eternal.”[327] The very intensity of that old Christian life under repression and persecution created a more imperious necessity for a religious symbolism as an expression of its deepest feelings and as a common sign of the faith. Early Christian art, therefore, was not realistic and sensuous, but ideal and 205 spiritual. It sought to express the inner essence, not the outer form.