The most sensible definition of magic is "an effect sought to be produced by antecedents obviously inadequate in themselves." Certain words, gestures, practices, have been recognised on the tradition of ancient experience to have certain remedial or other properties or consequents, and they are used in all simplicity by persons who can find no other reason than that they are thought to succeed.
One of the most remarkable of early ideas still current about human destiny is that which pictures each man coupled with a personal and individualised fate. This fate may be beneficent or maleficent, a guardian angel or a possessive fiend; or it may, in appearance at least, combine both functions. The belief in a personal fate was deeply rooted among the Greeks and Romans, and proved especially acceptable to the Platonists. Socrates' dæmon comes to mind: but in that case the analogy is not clear, because the inward voice to which the name of dæmon was afterwards given, was rather a personal conscience than a personal fate--a difference that involves the whole question of the responsibility of man. But the evil genii of Dion the Syracusan and of Brutus were plainly "personal fates." Dion's evil genius appeared to him when he was sitting alone in the portico before his house one evening; it had the form of a gigantic woman, like one of the furies as they were represented on the stage, sweeping the floor with a broom. It did not speak, but the apparition was followed by the death of Dion's son, who jumped in a fit of childish passion from the house-top, and soon after, Dion himself was assassinated. Brutus' dæmon was, as every-one knows, a monstrous spectre that seemed to be standing beside him in his tent one night, a little while before he left Asia, and which, on being questioned, said to him, "I am thy evil genius, Brutus, thou wilt see me at Philippi."
We catch sight again of the personal fate in the relations of Antony with the young Octavius. Antony had in his house an Egyptian astrologer, who advised him by all means to keep away from the young man, "for your genius," he said, "is in fear of his; when it is alone its port is erect and fearless, when his approaches it, it is dejected and depressed." There were circumstances, says Plutarch, that carried out this view, for in every kind of play, whether they cast lots or cast the die, Antony was still the loser; in their cock fights and quail fights, it was still "Cæsar's cock and Cæsar's quail."