The art of healing was originally one of the secret sciences of the priestcraft, and the mystery of its source is obscured by the same veil which hides the genesis of religious belief. All higher forms of knowledge were originally in the possession of the sacerdotal castes. The temple was the cradle of civilization. The priests, exercising their divine prerogative, made the laws and enforced them; appointed the rulers and controlled than; ministered to the needs of the living, and guided the destinies of the dead. All branches of learning were monopolized by the priesthood, who admitted into their ranks only those intellectually and morally qualified to perpetuate their arcanum.