With the consideration of Orphism it has become, I hope, abundantly clear why at the outset attention was focussed on the primitive rites of Aversion and Purification rather than on the Service of the Olympians. The ritual embodied in the formulary _do ut des_ is barren of spiritual content. The ritual embodied in _do ut abeas_ contains at least the recognition of one great mystery of life, the existence of evil. The rites of the Olympians were left untouched by the Orphics; the rites of purification and of sympathetic magic lent them just the symbolism they needed. Moreover even in theology the crude forms of demons were more pliant material for mysticism than the clear-cut limitations and vivid personality of the Olympians. Orphism was the last word of Greek religion, and the ritual of Orphism was but the revival of ancient practices with a new significance. * * * * * The reader will note that in the pages that follow, two authors, Plutarch and Euripides, have been laid under special contribution. Plutarch’s gentle conservatism made him cling tenaciously to antique faith. According to him, one function of religion was to explain and justify established rites, and in the course of his attempted justification he tells us many valuable ritual facts. Euripides, instant in his attack on the Olympian gods, yet treats with respect the two divinities of Orphism, Dionysos and Eros. I have suggested that, born as he was at Phlya, the ancient home of Orphic mysteries, his attitude on this matter may have been influenced by early associations. In any case, a religion whose chief divinities were reverently handled by Euripides cannot be dismissed as a decadent maleficent superstition. * * * * * I would ask that the chapters I have written be taken strictly as they are meant, as Prolegomena. I am deeply conscious that in surveying so wide a field I have left much of interest untouched, still more only roughly sketched in. I wished to present my general theory in broad outline for criticism before filling in details, and I hope in the future to achieve a study of Orphism that may have more claim to completeness. If here I have dwelt almost exclusively on its strength and beauty, I am not unaware that it has, like all mystical religions, a weak and ugly side. * * * * * If in these Prolegomena I have accomplished anything, this is very largely due to the many friends who have helped me; the pleasant task remains of acknowledging my obligations. * * * * *