The most striking personage of the old Hellenic religion that remains to be studied is Apollo. The investigation is always attractive for the student of pure Hellenism, and is of value also for the general history of European ethic and religious thought. Being certainly the brightest creation of polytheism, he is also the most complex; so many aspects of the people's life and progress being reflected in his cult. It may not, indeed, present us with the highest achievement of the Hellenic spirit in religious speculation: for instance, to trace the gradual evolution of ideas that made for monotheism, we must turn rather to the worship of Zeus. Nor, again, did it attempt to satisfy, as the Dionysiac and Eleusinian worships attempted, the personal craving for a happy immortality which was appealing strongly to the Hellenic world before the diffusion of Christianity. Currents of mystic speculation, coming partly from the East, and bringing new problems concerning the providence of the world and the destiny of the soul, scarcely touched and in no way transformed the personality of Apollo. A Panhellenic god, he survived almost down to the close of paganism as a brilliant and clearly-outlined figure of the genuinely national religion: and in reviewing his cults one is surveying the career of a people in its transition from the lower barbarism into the highest social and intellectual life.