It is clear that Plato — in thus laying down the principle of reciprocity, or interchange of service, as the ground-work of the social union — recognises the antithesis, and at the same time the correlation, between obligation and right. The service which each man renders to supply the wants of others is in the nature of an onerous duty; the requital for which is furnished to him in the services rendered by others to supply his wants. It is payment against receipt, and is expressly so stated by Plato — which every man conforms to, “believing that he will be better off thereby”. Taking the two together, every man is better off; but no man would be so by the payment alone; nor could any one continue paying out, if he received nothing in return. Justice consists in the proper carrying on of this interchange in its two correlative parts.[29]
[29] We may remark that Plato, though he states the principle of reciprocity very justly, does not state it completely. He brings out the reciprocity of need and service; he does not mention the reciprocal liability of injury. Each man can do hurt to others: each man may receive hurt from others. Abstinence on the part of each from hurting others, and security to each that he shall not be hurt by others, are necessities quite as fundamental as that of production and interchange.
The reciprocal feeling of security, or absence of all fear of ill-usage from others (τὸ καθ’ ἡμέραν ἀδεὲς καὶ ἀνεπιβούλευτον πρὸς ἀλλήλους, to use the phrase of Thucydides iii. 37), is no less essential to social sentiment, than the reciprocal confidence that each man may obtain from others a supply of his wants, on condition of supplying theirs.
We see therefore that Plato contradicts his own fundamental principle, when he denies the doing of justice to be an onerous duty, and when he maintains that it is in itself happiness-giving to the just agent, whether other men account him just and do justice to him in return — or not. By this latter doctrine he sets aside that reciprocity of want and service, upon which he had affirmed the social union to rest. The fathers, whom he blames, gave advice in full conformity with his own principle of reciprocity — when they exhorted their sons to the practice of justice, not as self-inviting, but as an onerous service towards others, to be requited by corresponding services and goodwill from others towards them. If (as he urges) such advice operates as an encouragement to crime, because it admits that the successful tyrant or impostor, who gets the services of others for nothing, is better off than the just man who gets them only in exchange for an onerous equivalent — this inference equally flows from that proclaimed reciprocity of need and service, which he himself affirms to be the generating cause of human society. If it be true (as Plato states) that each individual is full of wants, and stands in need of the services of others — then it cannot be true, that payment without receipt, as a systematic practice, is self-inviting and self-satisfying. That there are temptations for strong or cunning men to evade obligation and to usurp wrongful power, is an undeniable fact. We may wish that it were not a fact: but we gain nothing by denying or ignoring it. The more clearly the fact is stated, the better; in order that society may take precaution against such dangers — a task which has always been found necessary and often difficult. In reviewing the Gorgias,[30] we found Sokrates declaring, that Archelaus, the energetic and powerful king of Macedonia, who had usurped the throne by means of crime and bloodshed, was thoroughly miserable: far more miserable than he would have been, had he been defeated in his enterprise and suffered cruel punishment. Such a declaration represents the genuine sentiment of Sokrates as to what he himself would feel, and what ought to be (in his conviction) the feeling of every one, after having perpetrated such nefarious acts. But it does not represent the feeling of Archelaus himself, nor that of the large majority of bystanders: both to these latter, and to himself, Archelaus appears an object of envy and admiration.[31] And it would be a fatal mistake, if the peculiar sentiment of Sokrates were accepted as common to others besides, and as forming a sound presumption to act upon: that is, if, under the belief that no ambitious man will voluntarily bring upon himself so much misery, it were supposed that precautions against his designs were unnecessary. The rational and tutelary purpose of punishment is, to make the proposition true and obvious to all — That the wrong-doer will draw upon himself a large preponderance of mischief by his wrong-doing. But to proclaim the proposition by voice of herald (which Plato here proposes) as if it were already an established fact of human nature, independent of all such precautions — would be only an unhappy delusion.[32]
[30] See above, ch. xxiv., vol. ii., [pp. 325-29].
[31] Xenophon, Cyropæd. iii. 3, 52-53. Cyrus says:—
Ἆρ’ οὐκ, εἰ μέλλουσι τοιαῦται διάνοιαι ἐγγενήσεσθαι ἀνθρώποις καὶ ἔμμονοι ἔσεσθαι, πρῶτον μὲν νόμους ὑπάρξαι δεῖ τοιούτους, δι’ ὧν τοῖς μὲν ἀγαθοῖς ἔντιμος καὶ ἐλευθέριος ὁ βίος παρασκευασθήσεται, τοῖς δὲ κακοῖς ταπεινός τε καὶ ἀλγεινὸς καὶ ἀβίωτος ὁ αἰὼν ἐπανακείσεται; Ἔπειτα δὲ διδασκάλους, οἴμαι, δεῖ καὶ ἄρχοντας ἐπὶ τούτοις γενέσθαι, οἵτινες δείξουσί τε ὀρθῶς καὶ διδάξουσι καὶ ἐθίσουσι ταῦτα δρᾷν, ἔστ’ ἂν ἐγγένηται αὐτοῖς, τοὺς μὲν ἀγαθοὺς καὶ εὐκλεεῖς εὐδαιμονεστάτους τῷ ὄντι νομίζειν, τοὺς δὲ κακοὺς καὶ δυσκλεεῖς ἀθλιωτάτους ἁπάντων ἡγεῖσθαι.
Xenophon here uses language at variance with that of Plato, and consonant to that of the fathers of families whom Plato censures. To create habits of just action, and to repress habits of unjust action, society must meet both the one and the other by a suitable response. Assuming such conditional reciprocity to be realised, you may then persuade each agent that the unjust man, whom society brands with dishonour, is miserable (οἱ κακοὶ καὶ δυσκλεεῖς).
[32] Xenophon, Economic. xiii. 11. Ischomachus there declares:—
Πάνυ γάρ μοι δοκεῖ, ὦ Σώκρατες, ἀθυμία ἐγγίγνεσθαι τοῖς ἀγαθοῖς, ὅταν ὁρῶσι τὰ μὲν ἔργα δι’ αὐτῶν καταπραττόμενα, τῶν δὲ ὁμοίων τυγχάνοντας ἑαυτοῖς τοὺς μήτε πονεῖν μήτε κινδυνεύειν ἐθέλοντας, ὅταν δέῃ. — Also xiv. 9-10.