Priesthood was sometimes hereditary, but was not confined to a class. Kings, generals, and the heads of a family acted as priests and offered sacrifices. It was a temporary office, and Plato recommends that there should be an annual rotation, no man acting as priest for more than one year. Such a state of opinion excludes the danger of priestcraft, and is opposed to all hierarchal pretensions. The same, however, cannot be said of the diviners and soothsayers, who were so much consulted, and whose opinions determined so often the course of public affairs. They were often in the pay of ambitious men. Alcibiades had augurs and oracles devoted to his interests, who could induce the Athenians to agree to such a course as he desired. For the Greeks were extremely anxious to penetrate the future, and the power and influence of their oracles is, says Döllinger, a phenomenon unique in history. Among these oracles, Delphi, as is well known, took the highest rank. It was considered the centre of the earth, and was revered by the Pan-Hellenic race. It was a supreme religious court, whose decisions were believed to be infallible. The despotism of the Pythian decisions was, however, tempered by their ambiguity. Their predictions, if they failed, seldom destroyed the faith of the believers; for always some explanation could be devised to save the credit of the oracle. Thus, the Pythian promised the Athenians that they would take all the Syracusans prisoners. They did not take them; but as a muster-roll of the Syracusan army fell into their hands, this was considered to fulfil the promise.[259] Aristides, the rhetorician, was told that the "white maidens" would take care of him; and receiving a letter which was of advantage, he was fully convinced that this was the "white maiden." But neither imposition nor delusion will satisfactorily explain the phenomena connected with oracles. The foundation of them seems to have been a state allied to the modern manifestations of magnetic sleep and clairvoyance. "As the whole life of the Greeks," says Döllinger, "was penetrated by religion," they instinctively and naturally prayed on all occasions. They prayed at sunrise and sunset, at meal-times, for outward blessings of all kinds, and also for virtue and wisdom. They prayed standing, with a loud voice, and hands lifted to the heavens. They threw kisses to the gods with their hands. So we see that the Greek worship, like their theology, was natural and human, a cheerful and hopeful worship, free from superstition. This element only arrives with the mysteries, and the worship of the Cthonic gods. To the Olympic gods supplications were addressed as to free moral agents, who might be persuaded or convinced, but could not be compelled. To the under-world deities prayer took the form of adjuration, and degenerated into magic formulas, which were supposed to force these deities to do what was asked by the worshipper. § 8. The Mysteries. Orphism.