The Second Treatise of Civil Government 1690
That the aggressor, who puts himself into the state of war with another, and unjustly invades another man’s right, can, by such an unjust war, never come to have a right over the conquered, will be easily agreed by all men, who will not think that robbers and pirates have a right of empire over whomsoever they have force enough to master, or that men are bound by promises which unlawful force extorts from them.
Should a robber break into my house, and, with a dagger at my throat, make me seal deeds to convey my estate to him, would this give him any title? Just such a title by his sword has an unjust conqueror who forces me into submission. The injury and the crime is equal, whether committed by the wearer of a crown or some petty villain.
The title of the offender and the number of his followers make no difference in the offence, unless it be to aggravate it. The only difference is, great robbers punish little ones to keep them in their obedience; but the great ones are rewarded with laurels and triumphs, because they are too big for the weak hands of justice in this world, and have the power in their own possession which should punish offenders.
– John Locke – 1632-1704 – http://www.constitution.org/jl/2ndtreat.htm