Christianity presents a parallel case. In the beginning it sought only to call sinners to repentance. The strong, as Jesus himself said, do not require a physician, but the sick. He therefore looked upon himself as a physician, just as Buddha had done in an earlier day. He declared that he was not come to destroy the law, but to fulfil it. The truth of his teaching should be known by its fruits, and there is scarcely a trace in the Gospels of philosophical discussions, or even of attacks on the schools of Greek philosophy. But even here it was soon apparent that, for a practical reformation of conduct, a higher consecration is essential. It was admitted, as an Indian philosopher is reputed long since to have said to Socrates, that no one could understand the human element who had not first understood the divine. Men of Greek culture who felt themselves attracted by the moral principles of the little Christian congregations soon, however, wanted more. They had to defend the step which they had taken, and the Christianity which they wished to profess, or had professed, against their former friends and co-believers, and this soon produced the so-called apologies for Christianity, and expositions of the philosophical and theological views which constituted the foundation of the new teaching. A religion which was recruited only from poor sinners and tax-gatherers could scarcely have found entry into the higher circles of society, or maintained itself in lecture-rooms and palaces against the cultivated members of refined circles, if its defenders, like Buddha, had simply ignored all philosophical, especially all metaphysical, questions. How came it, then, that cultured men in high stations, entirely independent, professed Christianity? How did they make their friends and former co-believers understand that such a step was _bona fide_? In answering this question, we get help from Celsus, as well as his opponent, Origen.