For hundreds of thousands of years humans lived in stable societies. But with the advent of Civilization, this changed abruptly. Civilizations came and went in endless succession. There have been no shortage of reasons for this, but none has even come close to being satisfactory.
The reason for this is probably because human societies are extremely complex and difficult to understand - or in computer terms: difficult to model. Large numbers of feedback loops, both positive and negative, with different timings, and with different interactions, are in action at the same time.
Consider something much smaller: The Military's Plan For The Afghan War Surge, In One Giant Chart. Click on the image to get a full-size version. Five minutes looking at this, or even five seconds, will make you doubt Obama's war plan - if he even has one. You have to give the Pentagon credit though, for even trying to understand the problem. If it really tried to put it into operation, with some way to monitor what was going on in all these loops, I would be even more impressed.
My next course from the Learning Company, my Christmas present to myself, will be Understanding Complexity. I did take the class on Chaos Theory, which is also useful. It says chaotic systems which had been considered unpredictable, actually actually are predictable, but in some strange ways: they tend to flip back and forth between different stable states.
In human societies, these would be periods of increasing power, followed by disintegration and loss of power - and often even existence. The Babylonian Empire is been long forgotten, along with many others.
Society has Become Evil
Back in the earlier days of the Roman Republic, the good had the upper hand, but in the later days, just the opposite was true. Societies have inertia: once they start moving in a particular direction, they tend to keep moving that way.
American society has become evil - and this is no new observation. Obama's former pastor said "God damn America!", and he meant it. Obama, who had moved from the slums of Chicago to the White House, had to leave that honest, critical part of him behind.
The value of any social theory rests on its ability to describe social trends that were not obvious before. Evil is a concept we all understand easily, because we have all been exposed to it - and hopefully we have learned from our experience. As Freud discovered, we like to project evil onto external enemies - but we need to turn that finger around and point to ourselves - and I am no different. I am as evil as anyone else, because I am all too human.