The phenomenon of latency  

The past couple days I've been rereading what I've always thought was Freud's most gripping book, Moses and Monotheism. The first half is a kind of historical adventure where he maps out his bold hypothesis about the historical beginnings of the Jewish people and their faith; the second half (which I find rather less compelling) deals with the Jewish character in broad psychoanalytic generalities that most people would probably consider racist today. Still, it's fascinating, and it gives a sense of the scope Freud felt his ideas had.

Freud's single biggest problem in psychoanalyzing a society or a religion is this notion of inherited memory. In this case, the basis for much of his analysis is the premise that Moses was an Egyptian who led the Jews out of Egypt but was then murdered by his newly adopted people in the desert. But for those events to work their way back to the surface centuries later, they first have to remain in the collective subconscious:

I must admit that I have argued as if there were no question that there exists an inheritance of memory -- traces of what our forefathers experienced, quite independently of direct communication and of the influence of education by example. When I speak of an old tradition still alive in a people, of the formation of a national character, it is such an inherited tradition, and not one carried on by word of mouth, that I have in mind.

This would be spooky, except that it's pretty much laughable today. There is no biological inheritance of memory. And yet we can talk about a lot of mechanisms for collective memory that Freud didn't quite have at his disposal, arguably derived from his work -- for instance, surely we could see how religious rituals and symbols themselves could contain this kind of information (albeit less explicitly), even absent an oral tradition. And of course, once there's an actual text in place (an event Freud puts several hundred years later in this case), there could be powerful dissonances in that text for readers to internalize. Does this mean I buy his theory of monotheism? I don't know... but it certainly serve to demonstrate the stunning intellectual influence of the latency idea.