There were occasional imperial edicts against astrologers, it is true, and even sporadic persecution of them. But the explanation of such measures is belief, not scepticism, and they denote not disbelief in the art itself but disapproval of the use to which it was put—such as revealing the fate of the present and the name of the coming ruler. Almost every emperor had an astrologer at his court, and the historians of the period delighted in telling stories of astrologers who foretold their own deaths, or of monarchs who in vain attempted to thwart the decrees of fate.[150] Alexander Severus is said to have founded chairs of astrology salaried by the state and with provision for scholarships for students.[151] Occasional persecution perhaps made the _mathematici_ more highly valued, and the jibes of the satirists against astrologers and their followers attest rather than disprove the popularity of the art. Pliny the Elder and Tacitus asserted its great currency.[152] The best science of the Empire reflected to a considerable extent these superstitions sanctioned by public opinion, as our discussion of Seneca and Ptolemy will indicate in some detail. For the present we may observe how the great Galen—whose authority reduced to a single school the many quarreling medical sects of his day, was later implicitly accepted by the Arabs, and then dominated European medicine to the time of Paracelsus—was not above astrological medicine or the use of fantastical remedies. He displayed trust in amulets and believed that such things as the ashes of frogs or “hippocampi” have remedial power.[153] He held that the critical days of disease are largely influenced by the moon, and affirmed that we receive “the force of all the stars above.”[154] It should be noted moreover that in one passage, in giving expression to his zeal for astronomy as the handmaid of the healing art, Galen accused many physicians of paying no attention to the stars. But he asserted that in this neglect they were no true followers of the great Hippocrates, whom they extolled but never imitated, for Hippocrates had maintained that astronomy had no small bearing on the art of the physician and that geometry was its indispensable precursor.[155]