Magic was the supreme science because it raised its adepts out of the ordinary levels of humanity to a close relationship with the gods and creative powers. Nor was it a science to be had for the asking, 'for many were the wand-bearers and few the chosen.' Roman writers tell us that neophytes for the druidic priesthood often spent twenty years in severe study and training before being deemed fit to be called Druids. We need not, however, in this study enter into an exposition of the ordeals and trials of candidates seeking magical training, or else initiation into the Mysteries. There were always two schools to which they could apply, directly opposed in their government and policy--the school of white magic and the school of black magic; the former being a school in which magical powers were used in religious rites and always for good ends, the latter a school in which all magical powers were used for wholly selfish and evil ends. In both schools the preliminary training was the same; that is to say, the first thing taught to the neophyte was self-control. When he proved himself absolutely his own master, when his teachers were certain that he could not be dominated by another will or by any outside or psychic influence, then for the first time he was permitted to exercise his own iron will in controlling daemons, ghosts, and all the elemental hosts of the air--either as a white magician or as a black magician.[174] The magical sciences taught (an idea which still holds its ground, as one can discover in modern India) that by formulas of invocation, by chants, by magic sounds, by music, these invisible beings can be made to obey the will of the magician even as they obey the will of the gods. The calling up of the dead and talking with them is called necromancy; the foretelling through spiritual agency and otherwise of coming events or things hidden, like the outcome of a battle, is called divination; the employment of charms against children so as to prevent their growing is known as fascination; to cause any ill fortune or death to fall upon another person by magic is sorcery; to excite the sexual passions of man or woman, magical mixtures called philtres are used. Almost all these definitions apply to the practices of black magic. But the great schools known as the Mysteries were of white magic, in so far as they practised the art; and such men as Pythagoras, Plato, and Aeschylus, who are supposed to have been initiated into them, always held them in the highest reverence, though prohibited from directly communicating anything of their esoteric teachings concerning the origin and destiny of man, the nature of the gods, and the constitution of the universe and its laws.