E. Meyer, _Geschichte des Alterthums_, vol. ii., contains the first attempt to deal with Greek religion in the manner now required.
The Histories of Greece of Grote, Curtius, Abbott, and Holm.
Roscher, _Lexikon der griechischen, a Rômischen Mythologie_.
Gardner and Jevons, _Manual of Greek Antiquities_, 1895.
L. R. Farnell, _The Cults of the Greek States_, 1896-1907.
Williamowitz, _Homerische Untersuchungen_.
L. Campbell's Gifford Lectures on _Religion in Greek Literature_, 1898.
E. Caird, _The Evolution of Theology in the Greek Philosophers_, 1904.
Holwerda, in De la Saussaye, Third Edition.
Ramsay on "Religion of Greece and Asia Minor" in Hastings' _Bible Dictionary_.
S. Reinach, in _Oxford Proceedings_, vol. ii. p. 117, _sqq._
The Romans themselves at a certain period in their history identified their own gods with those of Greece, and borrowed largely both from Greek ritual and Greek mythology, so that they came to the conclusion that the Roman and the Greek religions were essentially the same. To the early Christian writers the religions of Greece and Rome form one system; and the world has retained the impression that there was one old pagan religion which assumed certain local differences in the two countries, but was substantially the same in both.
Roman Religion was different from Greek.--Now the fact is that while Greek religion conquered Rome, Italy had an older religion of its own, which was not annihilated by the more brilliant newcomer, but remained beside it and never entered into entire fusion with it. The Romans were not a thinking so much as an organising race; in politics they were far ahead of the rest of the world, but in thought and imagination they were children; and so it happened that they borrowed ideas and usages from neighbours on this side and on that, and organised the whole into a system they could use, the organism being their own, but only little of the contents.
We must therefore inquire, in the first place, as to the religion the Romans had before they came under the influence of Greek ideas. Their earliest religion is to be traced in the calendar of their sacred year, in the lists of gods preserved for us in the writings of the fathers, and in numberless usages and institutions descended from early times.