The sections on religion in Mommsen's _History of Rome_.
Wissowa, _Religion und Cultur der Römer_.
For the period of the Empire, Boissier's _La Religion Romaine_.
See also the work of Cumont, cited at the end of chapter x.
No contrast could well be greater than that between the German religion and that of India. In the one case we have a people full of vigour, but not yet civilised; in the other a people of high organisation and culture, but deficient in vigour; the former religion is one of action, the latter one of speculation. From the original Aryan faith, to which that of the Teutons most closely approximates, Indian religion is removed by two great steps. First we have as a variety of Aryan faith the Indo-Iranian religion, that of the undivided ancestors of Persians and Indians alike, in the dim period antecedent to the Aryan settlement of India. Of this religion, the common mother of those of Persia and of India, we shall give some sketch after we have made acquaintance with the gods of India, at the beginning of our Persian chapter. Indian religion is a variety of Indo-Iranian, which is a variety of the Aryan type. Neither its genealogy nor its character entitles it to be taken as a typical example of the Aryan religions. In literary chronology it is the earliest of them, inasmuch as its books are the oldest sacred literature of Aryan faith; but in point of development it is not an early but an advanced product. The absorbing interest it offers to the student of our science is due to the fact that it presents in an unbroken sequence a growth of religious thought, which, beginning with simple conceptions and advancing to a great priestly ritual, can be seen to pass into mysticism and asceticism, and thence to the rejection of all gods and rites, and a system of salvation by individual good conduct. Nowhere else can the progress of religion through what we might call its seven ages of life be seen so clearly, nor the logical connection of these ages with each other be recognised so unmistakably. The present chapter deals with the infancy and lusty youth of the religion as seen in Vedism; the later stages of Brahmanism and Buddhism will be spoken of in subsequent chapters.