What causes a civilization to fall?

Also a Civilization could fall for any reason from killing the king to starting war inside

Explanation:

From the collapse of ancient Rome to the fall of the Mayan empire, evidence from archaeology suggests that five factors have almost invariably been involved in the loss of civilizations: uncontrollable population movements; new epidemic diseases; failing states leading to increased warfare; collapse of trade routes

yes, since there is a positive and a negetive if the positive and negitive wasn't there wouldn't a flow electricity in it.

answer; belief perseverance;