Plato, Laws 767a

τὰς ἀμφισβητουμένας πράξεις, ἐὰν δʼ ἄρα μὴ ἐν τούτοις τις ἱκανὴν κρίσιν λαμβάνῃ, πρὸς ἄλλο δικαστήριον ἴτω· τὸ δὲ τρίτον, ἂν τὰ δύο δικαστήρια μὴ δύνηται διαλλάξαι, τέλος ἐπιθέτω τῇ δίκῃ.τρόπον δή τινα καὶ τῶν δικαστηρίων αἱ καταστάσεις ἀρχόντων εἰσὶν αἱρέσεις· πάντα μὲν γὰρ ἄρχοντα ἀναγκαῖον καὶ δικαστὴν εἶναί τινων, δικαστὴς δὲ οὐκ ἄρχων καί τινα τρόπον ἄρχων οὐ πάνυ φαῦλος γίγνεται τὴν τόθʼ ἡμέραν ᾗπερ ἂν κρίνων τὴν δίκην ἀποτελῇ. θέντες δὴ καὶ τοὺς

the actions in dispute: if a man fails to get an adequate decision from them, he shall repair to another court; and if these two courts are unable to settle the matter, the third court shall put an end to the case. In a sense we may say that the establishment of law-courts coincides with the election of officials; for every official must be also a judge of certain matters, while a judge, even if not an official, may be said to be an official of no little importance on the day when he concludes a suit by pronouncing his judgment.