Plato: The tyrant is always stirring up war, the oligarchy uses force of arms to gain power
From The Republic
Translated by Benjamin Jowett
Socrates: But when he [the tyrant] has disposed of foreign enemies by conquest or treaty, and there is nothing to fear from them, then he is always stirring up some war or other, in order that the people may require a leader.
Glaucon and Socrates:
And what manner of government do you term oligarchy?
A government resting on a valuation of property, in which the rich have power and the poor man is deprived of it.
I understand, he replied.
Ought I not to begin by describing how the change from timocracy to oligarchy arises?
Well, I said, no eyes are required in order to see how the one passes into the other.
The accumulation of gold in the treasury of private individuals is the ruin of timocracy; they invent illegal modes of expenditure; for what do they or their wives care about the law?
And then one, seeing another grow rich, seeks to rival him, and thus the great mass of the citizens become lovers of money.
And so they grow richer and richer, and the more they think of making a fortune the less they think of virtue; for when riches and virtue are placed together in the scales of the balance, the one always rises as the other falls.
And in proportion as riches and rich men are honoured in the State, virtue and the virtuous are dishonoured.
And what is honoured is cultivated, and that which has no honour is neglected.
That is obvious.
And so at last, instead of loving contention and glory, men become lovers of trade and money; they honour and look up to the rich man, and make a ruler of him, and dishonour the poor man.
They do so.
They next proceed to make a law which fixes a sum of money as the qualification of citizenship; the sum is higher in one place and lower in another, as the oligarchy is more or less exclusive; and they allow no one whose property falls below the amount fixed to have any share in the government. These changes in the constitution they effect by force of arms, if intimidation has not already done their work.
And this, speaking generally, is the way in which oligarchy is established.