” … In Egypt attempts like that of Isis to appropriate the power of a high god by possessing herself of his name were not mere legends told of the mythical beings of a remote past; every Egyptian magician aspired to wield like powers by similar means.
For it was believed that he who possessed the true name possessed the very being of god or man, and could force even a deity to obey him as a slave obeys his master. Thus the art of the magician consisted in obtaining from the gods a revelation of their sacred names, and he left no stone unturned to accomplish his end. When once a god in a moment of weakness or forgetfulness had imparted to the wizard the wondrous lore, the deity had no choice but to submit humbly to the man or pay the penalty of his contumacy.
The belief in the magic virtue of divine names was shared by the Romans. When they sat down before a city, the priests addressed the guardian deity of the place in a set form of prayer or incantation, inviting him to abandon the beleaguered city and come over to the Romans, who would treat him as well as or better than he had ever been treated in his old home.
Hence the name of the guardian deity of Rome was kept a profound secret, lest the enemies of the republic might lure him away, even as the Romans themselves had induced many gods to desert, like rats, the falling fortunes of cities that had sheltered them in happier days.
Nay, the real name, not merely of its guardian deity, but of the city itself, was wrapt in mystery and might never be uttered, not even in the sacred rites. A certain Valerius Soranus, who dared to divulge the priceless secret, was put to death or came to a bad end.
In like manner, it seems, the ancient Assyrians were forbidden to mention the mystic names of their cities; and down to modern times the Cheremiss of the Caucasus keep the names of their communal villages secret from motives of superstition.”