The first book of his work(202) dragged to light some of the discrepancies, real or supposed, in scripture; and the examination of the dispute between St. Peter and St. Paul was quoted as an instance of the admixture of human ingredients in the body of apostolic teaching. His third book(203) was directed to the subject of scripture interpretation, especially, with some inconsistency, against the allegorical or mystical tendency which at that time marked the whole church, and especially the Alexandrian fathers. The allegorical method coincided with, if it did not arise from, the oriental instinct of symbolism, the natural poetry of the human mind. But in the minds of Jews and Christians it had been sanctified by its use in the Hebrew religion, and had become associated with the apocryphal literature of the Jewish church. It is traceable to a more limited extent in the inspired writers of the New Testament, and in most of the fathers; but in the school of Alexandria(204) it was adopted as a formal system of interpretation. It is this allegorical system which Porphyry attacked. He assaulted the writings of those who had fancifully allegorised the Old Testament in the pious desire of finding Christianity in every part of it, in spite of historic conditions; and he hastily drew the inference, with something like the feeling of doubt which rash interpretations of prophecy are in danger of producing at this day, that no consistent sense can be put upon the Old Testament. His fourth book(205) was a criticism on the Mosaic history, and on Jewish antiquities. But the most important books in his work were the twelfth(206) and thirteenth,(207) which were devoted to an examination of the prophecies of Daniel, in which he detected some of those peculiarities on which modern criticism has employed itself, and arrived at the conclusions in reference to its date, revived by the English deist Collins in the last century, and by many German critics in the present.