Tiberius could not study astronomy or any other branch of science in his own day without being suspected of magic and divination; the things were almost mutually convertible terms, but the ancients had made considerable advances in the direction of the applied sciences, and had found out many working hypotheses, which were strictly scientific so far as the then sources of information allowed, even though further researches have proved them to be untenable. We should do injustice to Tiberius if we believed, as his contemporaries were ready to believe, that he spent his time at Rhodes in casting the horoscopes of himself and all other persons in whose destiny he had reason to be interested; but at the same time we must admit that the dividing line between science and pure charlatanry scarcely existed in those days, and that men such as Simon Magus and Elymas the Sorcerer frequently mistook the nature of their own proficiencies. Along with much sound astronomical knowledge, and with many equally sound results of experimental research, the East sent through various channels to the West a strange farrago of religion and so-called magical arts in which the esoteric learning of the Magicians, the Chaldeans, the Jews, the Greeks, the Egyptians, and even the Brahmins, was monstrously mixed up with popular superstitions and wilful imposture. The strong common sense which Tiberius exhibited in his public actions at a later time forbids us to believe that he lost his head at this period in hazardous and illusory speculations. We know that he took his place as an ordinary citizen of a free Greek town, and joined in the debates of its assembly, that he attended the lectures of the professors, and that his chosen associate was Thrasyllus, “a mathematician.” There is a pleasant story to the effect that Tiberius once went to a schoolmaster at Rhodes who called himself Diogenes, and was used to lecture on Sabbath days, asking for the honour of a special audience. Diogenes did not even admit him, but sent a verbal message by a dirty little slave boy, bidding him come back on the seventh day. Tiberius took no notice of the rudeness at the time, but when, after he had become Emperor, he was told that Diogenes was waiting outside his door at Rome in order to convey his congratulations, he sent out to tell him to come back in seven years.