"Usually it was the lower-class majority that wanted to side with Athens, and the well-heeled minority that wanted to side with Sparta. The consequent struggles attenuated or nullified all of the bonds that make a group of people into a state. Ancient and sacred laws of religious amnesty were violated. Fathers killed their sons. Besides which—and this is what’s been keeping me up at night—words lost their meaning. Here is what Thucydides writes (3.82, my translation):
They even changed the agreed-upon meanings of words to the opposite of the right ones. Rash impudence was called “courageous loyalty”; careful deliberation, “specious cowardice”…. Getting revenge was considered better than never being wronged in the first place…. The cause of all this was hunger for power motivated by greed and ambition.
Social upheaval, in other words, presents an opportunity for would-be autocrats to make a grab for power by weakening the foundations of legitimate rule. Those foundations are: piety, family, and language."