Synesius (370–430 A. D.), Bishop of Ptolemais, furnishes a good example of what was probably the position of the average Neo-Platonist who did not go to extremes in the last period of the Roman Empire. In the present survey we are not concerned with Christian belief in the Empire, and so it is only as a Neo-Platonist that Synesius will at present interest us. He is the more interesting for us in that he was a man with some taste for science. He knew some medicine and was well acquainted with geometry and astronomy, subjects which he probably studied under his friend Hypatia. He believed himself to be the inventor of an astrolabe and of a hydroscope. He played his part in secular politics and as bishop defended his people from oppression. He was fond of the chase and of his dogs and horses, and said so. He was a great lover of books also, but thought that their true use was to call one’s own mental powers into action. Philosophy, mathematics and literature all claimed his attention. Yet broad and independent-minded as he was for his age, and interested as he was in science, he believed in magic. Indeed, there was apparently no form of magic in which he would not have believed. Synesius regarded the universe as a unit and all its parts as closely correlated. This belief not only led him to maintain, like Seneca, that whatever had a cause was a sign of some future event, or to hold with Plotinus that in any and every object the sage might discern the future of every other thing, and that the birds themselves, if endowed with sufficient intelligence, would be able to predict the future by observing the movements of human bipeds.[226] It led him also to the conclusion that the various parts of the universe were more than passive mirrors in which one might see the future of the other parts; that they further exerted, by virtue of the magic sympathy which united all parts of the universe, a potent active influence over other objects and occurrences. The wise man might not only predict the future; he might, to a great extent, control it. For it must be, I think, that of this whole, so joined in sympathy and in agreement, the parts are closely connected as if members of a single body. And does not this explain the spells of the magi? For things, besides being signs of each other, have magic power over each other. The wise man, then, is he who knows the relationships of the parts of the universe. For he draws one object under his control by means of another object, holding what is at hand as a pledge for what is far away, and working through sounds and material substances and forms.[227]