The borrowed materials of this philosophy were made by its founder into a veritable system. It included, potentially at least, the popular beliefs, which, however, interested this metaphysical Copt very little. But in those superstitious centuries, before as well as after him, these cruder elements were gathered and made much of by men of note. There was a tendency to contrast the spiritual and real with the manifold of material nonentity, and a cognate tendency to emphasize the opposition between the spiritual and good, and the material and evil, or between opposing spiritual principles. With less metaphysical people such opposition would take more entrancing shapes in the battles of gods and demons. Probably it would cause ascetic repression of the physical passions. Both tendencies had shown themselves before Plotinus came to build them into his system. Friend Plutarch, for instance, of Chaeroneia, was a man of pleasant temper and catholic curiosity. His philosophy was no great matter. He was gently credulous, and interested in anything marvellous and every imaginable god and demon. This good Greek was no ascetic, and yet had much to say of the strife between the good and evil principle. Like thoughts begat asceticism in men of a different temperament; for instance in the once famous Apollonius of Tyana and others, who were called Neo-Pythagoreans, whatever that meant. Such men had also their irrationalities, which perhaps made up the major part of their natures. They did indeed belong to those centuries when Astrology flourished at the imperial Court,[38] and every mode of magic mystery drew its gaping votaries; when men were ravenously drawing toward everything, except the plain concrete fact steadily viewed and quietly reasoned on. But it was within the schools of Neo-Platonism, in the generations after Plotinus, that these tendencies flourished, beneath the shelter of his elastic principles. Here three kindred currents made a resistless stream: a transcendental, fact-compelling dialectic; unveiled recognition of the supreme virtue of supra-rational convictions and experiences; and an asceticism which contemned matter and abhorred the things of sense. What more was needed to close the faculties of observation, befool the reason, and destroy knowledge in the end?