The truth is that the history of the last couple of thousand years has been broadly repeated attempts by various people or institutions - in a Freudian way - to rediscover the lost childhood of Europe, this golden age of peace and prosperity under the Romans, by trying to unify it.
The disruptive powers of excessive national fecundity may have played a greater part in bursting the bonds of convention than either the power of ideas or the errors of autocracy.