With the publication of this volume the self-imposed task that has occupied my intervals of leisure throughout twenty years is at last completed. But the fulfilment of the promise of the title is incomplete; for it has happened, according to the anticipation expressed in the preface to my third volume, that no room could be found for a full account of hero-worship and the cults of the dead and of the various ideas thereto attaching. I hope to be able subsequently to publish in a different setting the various materials I have gathered under this head and the conclusions that I have drawn from them. Apart from this omission, a work of the present compass, carried on through so long a period of one's life, is scarcely likely in its final form to satisfy either the writer or his readers. I may hope, however, to have shown myself amenable to the influence of all criticism that was meant to be helpful, and of the newer theories that in recent years have presented the problems of ancient religion in a new light. Though it has absorbed more time than I had supposed it would demand, I rejoice to have chosen and pursued this theme, for I at least, if no one else, have derived from it both mental profit and pleasure.