They who retire themselves from the common offices, from that infinite number of troublesome rules that fetter a man of exact honesty in civil life, are in my opinion very discreet.

Montaigne

Let us boldly appeal to those who are in public affairs; let them lay their hands upon their hearts, and then say whether, on the contrary, they do not rather aspire to titles and offices and that tumult of the world to make their private advantage at the public expense. The corrupt ways by which in this our time they arrive at the height to which their ambitions aspire, manifestly enough declares that their ends cannot be very good. 

Michel de Montaigne

Virtue and ambition, unfortunately, seldom lodge together.

Michel de Montaigne

[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