And yet, Rome borrowed from far more than the Greeks. Norse deities are popular, and seemingly more recognizable than classical Greek myth to those in North America with whom I've spoke about such things. Rome was taken over by a particular flavor of Christianity, which was changed by the Empire at least as much as it changed the Empire, and changed more by those who claimed it. (Christmas and Easter are not originally Christian holidays.) "Protestant" now, means a lot of different things to a lot of different people. The Renaissance was significantly tied to the Muslim world's own traditions of Civilization, and a major thrust of contemporary politics is that the Enlightenment was not a positive thing. And hardly anyone is a farmer anymore, even though that's what 90% of Western Civilization was until the last century or so. So yes, all of those influence any definition of Western Civilization, but they're neither some direct line of succession, nor a list of the most massive influences - they're a selection of popular nodes in a vast web of connections.