A comparison of the forms observed in these regions, both in regard to the minute details and to the general underlying ideas, ought to contribute independent evidence to the solution of our question. The transmission of precise rules of ritual from one people to another, implies an intercourse of some duration, and more or less regulated; for while the name of a god or a single myth is volatile, and can be wafted down remote routes by an itinerant trader, or nomad, or hunter, the introduction of any organised ritual implies, as a rule, the presence of the missionary or the foreign priest. If, then, there is any evidence suggesting that Greece in its earliest period learnt its ritual from Babylon, the importance of this for the ethnic history of religion will be great indeed. Therefore it may seem that a detailed comparison of the Eastern and Western ritual is forced upon us at this point: but it would be premature to expect at present any finality in the result, because the Mesopotamian documents have only been very incompletely examined and published by the linguistic experts. However, the material that they have presented to us reveals certain salient facts of immediate value for our present purpose that cannot be wholly illusory, however much we may have to modify our interpretation of them in the light of future discovery. {222} As regards the Greek evidence, we are not without fairly ample testimony concerning the earliest period. The Homeric poems present us with the contemporary religious practices of at least a portion of the population whom we may conveniently call the Achaeans; though we have no right to suppose that they give us a complete account even of those. Again, as ritual does not spring up in a day, and has a singular longevity, we may be sure that much of Homeric ritual is a tradition of the second millennium. Furthermore, we can supplement Homer by later testimony, of which the lateness of date is no argument against the primitiveness of the fashions that it may attest.