Full Idea
Justice (fairness) originates among approximately equal powers, as Thucydides (in the horrifying conversation between the Athenian and Melian envoys) rightly understood.
Clarification
Melos had surrendered to Athens, and was then cruelly treated
Gist of Idea
Justice (fairness) originates among roughly equal powers (as the Melian dialogues show)
Source
Friedrich Nietzsche (Human, All Too Human [1878], 092)
Book Reference
Nietzsche,Friedrich: 'Human, All Too Human', ed/tr. Faber,Marion [Penguin 1994], p.64
A Reaction
The moral position of the powerless is a notorious problem for social contract theories of morality. They have nothing to offer in a mere contract.