[Footnote 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 ([Greek: to\ kath' ê(me/ran a)dee\s kai\ a)nepibou/leuton pro\s a)llê/lous], 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