The Gnostic and Manichæan heresies which infested the Church during the first five or six centuries could not be without their influence in exalting the power of the principle of evil; but writers of a far more philosophical character and more sober tone than those Oriental heresiarchs cannot be exempted from the charge of having contributed fairly to the same result. Of those fathers of the Church who did not, like Arnobius and Lactantius, exclaim against all philosophy, as opposed to the simplicity of the gospel, the greater number belonged to the Alexandrian school of Neo-Platonists, who, with all their sublime idealism, are known to have cherished, with a peculiar fondness, some of the most childish and superstitious notions to which philosophic mysticism has given birth. No lover of piety and virtue springing from a high and soul-ennobling philosophy, but must love and reverence the memory of such names as Proclus, Plotinus, and Jamblichus. It cannot, however, be denied that the overstrained ideas of these pure spirits went a great way to promote the growth of the prevalent superstitions with regard to theurgy and magic. The life of Plotinus seems, from the account given by Porphyry, to have been considered by himself and his admirers as an uninterrupted intercourse with spiritual intelligences, yea, with the one original Spirit himself; and in the Enneads of this prince of philosophic mystics, we have already fully developed all that system of mutual sympathies and antipathies, of concords and discords, between the all-animated parts of that mighty animal the World, which so readily allowed themselves to be worked into a system of practical theurgy and magic. Jamblichus, again, was not only a mystical philosopher, who sought to arrive at union (ἕνωσις) with the Divine Being by intellectual contemplation, but a magician and theurgist, as his work on the Egyptian mysteries, and the many legends told of him by his biographers, sufficiently prove.