[Pericles] told them to wait quietly, to pay attention to their marine, to attempt no new conquests, and to expose the city to no hazards during the war, and doing this, promised them a favourable result. What they did was the very contrary, allowing private ambitions and private interests, in matters apparently quite foreign to the war, to lead them into projects unjust both to themselves and to their allies— projects whose success would only conduce to the honour and advantage of private persons, and whose failure entailed certain disaster on the country in the war.... each grasping at supremacy, they ended by committing even the conduct of state affairs to the whims of the multitude.

Thucydides, The History of the Peloponnesian War