to the worship of Mary, and whose orgiastic service he describes and reprobates: in their processions they appear to have drawn the Virgin round in a car strewn with raiment, and they solemnised a sacrament with bread: and he adds that they came from Thrace, the immemorial home of fanatic women and of the goddess “Artemis the Queen,” to whom also offerings of corn were made.[72.3] The procession of a goddess in a car was probably part of an old Thrako-Phrygian {73} ceremonial, and we hear of a sacramental eating of bread in the service of Cybele. We may finally note that the enthusiastic literature devoted to the pre-Christian Divine Mother and Maid and to the Virgin-Mother of God is the same in quality and tone. The prayer addressed to Isis in the story of Apuleius reminds us of a Christian hymn of praise; and the older liturgical or literary expressions would naturally colour the later.[73.1] Another question with which the comparative study of Christianity is concerned touches the evolution of the Trinitarian idea.[73.2] Here {74} again it is necessary carefully to sift the phenomena of the contiguous religions, to consider whether they present such a conception at all, and whether in any of them it had gained sufficient vividness and power to be likely to evoke a dogma of religious metaphysic. Moreover, to understand the complete genesis of the Christian doctrine, we must trace out the idea of divine emanations in the Mediterranean and the East; for the religions of the Iranian and even the Greek world present us with parallels to the process whereby the Holy Spirit becomes in relation to the personal God a distinct though closely attached personality. In the Zoroastrian ritual the Fravashi or Soul of Ahura receives reverence,[74.1] and in Greek speculation and even cult the θεοῦ Πρόνοια or Divine Providence is sometimes regarded as an individual and {75} personal power;[75.1] nor is the conception of a plurality of beings within the limits of the same personality unfamiliar to primitive thought. The subject is one of the most intricate in the field of religious study, and the more hopeful investigation of it would demand anthropological study in its widest sense, combined with a knowledge of the later Greek metaphysic which has clearly left its impress on our doctrine.