One of the most remarkable phenomena belonging to this branch of magic is the appearance of living or recently deceased persons to friends or supplicants. The peculiarity in this case consists in the constantly changing character of the appearance: the double--as it is called--is the vision of the dying man, which appears to others or to his own senses. The former class of cases was well known in antiquity, for Pythagoras already had, according to popular report, appeared to numerous friends before he died. Herodotus and Maximus Tyrius state both, that Aristæus sent his spirit into different lands to acquire knowledge, and Epimenides and Hernestinus, from Claromenæ, were popularly believed to be able to visit, when in a state of ecstasy, all distant countries, and to return at pleasure. St. Augustine, also, states ("Sermon," 123) that he, himself, had appeared to two persons who had known him only by reputation, and advised them to go to Hippons in order to obtain their health there by the intercession of St. Stephen. They really went to the place and recovered from their disease. At another time his form appeared to a famous teacher of eloquence in Carthage and explained to him several most difficult passages in Cicero's writings (_De cura pro mortuis_, ch. ii). The saints of the Catholic church having possessed the gift of being in several places at once, apparently so very generally, that the miracle has lost its interest, except where peculiar circumstances seem to suggest the true explanation. Such was, for instance, the last-mentioned case, recited by St. Augustine (_De Civ. Dei._ l. 8. ch. 18). Præstantius requested a philosopher to solve to him some doubts, but received no answer. The following night, however, when Præstantius lay awake, troubled by his difficulties, he suddenly saw his learned friend standing by his bedside and heard from his lips all he desired to know. Upon meeting him next day, he inquired why he had been unwilling to explain the matter in the daytime, and thus caused himself the trouble of coming at midnight to his house. "I never came to your house," was the reply, "but I dreamt that I did." Here was very evidently a case of magic activity on the part of the philosopher, whose mind was, in his sleep, busily engaged in solving the propounded mystery and thus affected not himself only, but his absent friend likewise.