Full Idea
There is no such things as justice in itself; in people's relations with one another in any place and at any time it is a contract about not harming or being harmed.
Gist of Idea
Justice is merely a contract about not harming or being harmed
Source
Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 33), quoted by Julia Annas - The Morality of Happiness 13.2
Book Reference
Annas,Julia: 'The Morality of Happiness' [OUP 1995], p.294