Let us note the sentiment in which Plato’s creed here originates. He desires, above every thing, to stand forward as the champion and panegyrist of justice — as the enemy and denouncer of injustice. To praise justice, not in itself, but for its consequences — and to blame injustice in like manner — appears to him disparaging and insulting to justice.[11] He is not satisfied with showing that the just man benefits others by his justice, and that the unjust man hurts others by his injustice: he admits nothing into his calculation, except happiness or misery to the agent himself: and happiness, moreover, inherent in the process of just behaviour — misery inherent in the process of unjust behaviour — whatever be the treatment which the agent may receive from either Gods or men. Justice per se (affirms Plato) is the cause of happiness to the just agent, absolutely and unconditionally: injustice, in like manner, of misery to the unjust — quand même — whatever the consequences may be either from men or Gods. This is the extreme strain of panegyric suggested by Plato’s feeling, and announced as a conclusion substantiated by his reasons. Nothing more thoroughgoing can be advanced in eulogy of justice. “Neither the eastern star nor the western star is so admirable” — to borrow a phrase from Aristotle.[12]
[11] Plato, Republic, ii. p. 368 B-C. δέδοικα γὰρ μὴ οὐδ’ ὅσιον ᾖ παραγενόμενον δικαιοσύνῃ κακηγορουμένῃ ἀπαγορεύειν καὶ μὴ βοηθεῖν, &c.
[12] Aristot. Ethic. Nikom. v. 3 (1), 1129, b. 28. οὔθ’ ἕσπερος οὔθ’ ἑῷος οὕτω θαυμαστός.
Plato is here the first proclaimer of the doctrine afterwards so much insisted on by the Stoics — the all-sufficiency of virtue to the happiness of the virtuous agent, whatever may be his fate in other respects — without requiring any farther conditions or adjuncts. It will be seen that Plato maintains this thesis with reference to the terms justice and its opposite injustice; sometimes (though not often) using the general term virtue or wisdom, which was the ordinary term with the Stoics afterwards.
Different senses of justice — wider and narrower sense.
The ambiguous meaning of the word justice is known to Plato himself (as it is also to Aristotle). One professed purpose of the dialogue called the Republic is to remove such ambiguity. Apart from the many other differences of meaning (arising from dissentient sentiments of different men and different ages), there is one duplicity of meaning which Aristotle particularly dwells upon.[13] In the stricter and narrower sense, justice comprehends only those obligations which each individual agent owes to others, and for the omission of which he becomes punishable as unjust — though the performance of them, under ordinary circumstances, carries little positive merit: in another and a larger sense, justice comprehends these and a great deal more, becoming co-extensive with wise, virtuous, and meritorious character generally. The narrower sense is that which is in more common use; and it is that which Plato assumes provisionally when he puts forward the case of opponents in the speeches of Glaukon and Adeimantus. But when he comes to set forth his own explanation, and to draw up his own case, we see that he uses the term justice in its larger sense, as the condition of a mind perfectly well-balanced and well-regulated: as if a man could not be just, without being at the same time wise, courageous, and temperate. The just man described in the counter-pleadings of Glaukon and Adeimantus, would be a person like the Athenian Aristeides: the unjust man whom they contrast with him, would be one who maltreats, plunders, or deceives others, or usurps power over them. But the just man, when Sokrates replies to them and unfolds his own thesis, is made to include a great deal more: he is a person in whose mind each of the three constituent elements is in proper relation of controul or obedience to the others, so that the whole mind is perfect: a person whose Reason, being illuminated by contemplation of the Universals or self-existent Ideas of Goodness, Justice, Virtue, has become qualified to exercise controul over the two inferior elements: one of which (Energy) is its willing subordinate and auxiliary — while the lowest of the three (Appetite) is kept in regulation by the joint action of the two. The just man, so described, becomes identical with the true philosopher: no man who is not a philosopher can be just.[14] Aristeides would not at all correspond to the Platonic ideal of justice. He would be a stranger to the pleasure extolled by Plato as the exclusive privilege of the just and virtuous — the pleasure of contemplating universal Ideas and acquiring extended knowledge.[15]
[13] Aristotel. Eth. Nikom. v. 2 (1), 1129, a. 25. ἔοικε δὲ πλεοναχῶς λέγεσθαι ἡ δικαιοσύνη καὶ ἡ ἀδικία.
Also v. 3 (1), 1130, a. 3. διὰ δὲ τὸ αὐτὸ τοῦτο καὶ ἀλλότριον ἀγαθὸν δοκεῖ εἶναι ἡ δικαιοσύνη, μόνη τῶν ἀρετῶν, ὅτι πρὸς ἕτερον ἐστιν· ἄλλῳ γὰρ τὰ συμφέροντα πράττει, ἢ ἄρχοντι ἢ κοινῷ.
This proposition — that justice is ἀλλότριον ἀγαθόν — is the very proposition which Thrasymachus is introduced as affirming and Sokrates as combating, in the first book of the Republic.
Compare also Aristotle’s Ethica Magna, i. 34, p. 1193, b. 19, where the same explanation of justice is given: also p. 1194, a. 7, where the Republic of Plato is cited, and the principle of reciprocity, as laid down at the end of the second book of the Republic, is repeated. We read in a fragment of the lost treatise of Cicero, De Republicâ (iii. 6, 7):— “Justitia foras spectat, et projecta tota est atque eminet. — Quæ virtus, præter cæteras, tota se ad alienas porrigit utilitates atque explicat.”