Plato, Laws 768b

ἑκατέρου. δεῖ δὲ δὴ καὶ τῶν ἰδίων δικῶν κοινωνεῖν κατὰ δύναμιν ἅπαντας· ὁ γὰρ ἀκοινώνητος ὢν ἐξουσίας τοῦ συνδικάζειν ἡγεῖται τὸ παράπαν τῆς πόλεως οὐ μέτοχος εἶναι. διὰ ταῦτʼ οὖν δὴ καὶ κατὰ φυλὰς ἀναγκαῖον δικαστήριά τε γίγνεσθαι καὶ κλήρῳ δικαστὰς ἐκ τοῦ παραχρῆμα ἀδιαφθόρους ταῖς δεήσεσι δικάζειν, τὸ δὲ τέλος κρίνειν πάντων τῶν τοιούτων ἐκεῖνο τὸ δικαστήριον, ὅ φαμεν εἴς γε ἀνθρωπίνην δύναμιν ὡς οἷόν τε ἀδιαφθορώτατα παρεσκευάσθαι τοῖς μὴ

the choice of each of them. In private suits also, so far as possible, all the citizens must have a share; for the man that has no share in helping to judge imagines that he has no part or lot in the State at all. Therefore there must also be courts for each tribe, and judges appointed by lot and to meet the sudden occasion must judge the cases, unbiased by appeals; but the final verdict in all such cases must rest with that court which we declare to be organized in the most incorruptible way that is humanly possible,