The reader will please remember that the different chapters were thought out and written as lectures. They do not claim to contain a debit and credit account of what the Latin paganism borrowed from or loaned to the Orient. Certain well-known facts have been {xvi} deliberately passed over in order to make room for others that are perhaps less known. We have taken liberties with our subject matter that would not be tolerated in a didactic treatise, but to which surely no one will object. We are more likely to be reproached for an apparently serious omission. We have investigated only the internal development of paganism in the Latin world, and have considered its relation to Christianity only incidentally and by the way. The question is nevertheless important and has been the subject of celebrated lectures as well as of learned monographs and widely distributed manuals.[2] We wish to slight neither the interest nor the importance of that controversy, and it is not because it seemed negligible that we have not entered into it. By reason of their intellectual bent and education the theologians were for a long time more inclined to consider the continuity of the Jewish tradition than the causes that disturbed it; but a reaction has taken place, and to-day they endeavor to show that the church has borrowed considerably from the conceptions and ritualistic ceremonies of the pagan mysteries. In spite of the prestige that surrounded Eleusis, the word "mysteries" calls up Hellenized Asia rather than Greece proper, because in the first place the earliest Christian communities were founded, formed and developed in the heart of Oriental populations, Semites, Phrygians and Egyptians. Moreover the religions of those people were much farther advanced, much richer in ideas and sentiments, more striking and stirring than the Greco-Latin anthropomorphism. Their liturgy always derives its inspiration from generally accepted beliefs {xvii} about purification embodied in certain acts regarded as sanctifying. These facts were almost identical in the various sects. The new faith poured its revelation into the hallowed moulds of earlier religions because in that form alone could the world in which it developed receive its message. This is approximately the point of view adopted by the latest historians.