This theory respecting justice and injustice was first introduced into ethical speculation by Plato. He tells us himself (throughout the speeches ascribed to Glaukon and Adeimantus), that no one before him had announced it: that all with one accord[18]--both the poets in addressing an audience, and private citizens in exhorting their children--inculcated a different doctrine, enforcing justice as an onerous duty, and not as a self-recommending process: that he was the first who extolled justice in itself, as conferring happiness on the just agent, apart from all reciprocity or recognition either by men or Gods--and the first who condemned injustice in itself, as inflicting misery on the unjust agent, independent of any recognition by others. Here then we have the first introduction of this theory into ethical speculation. Injustice is an internal taint, corruption of mind, which (like bad bodily health) is in itself misery to the agent, however he may be judged or treated by men or Gods; and justice is (like good bodily health) a state of internal happiness to the agent, independent of all recognition and responsive treatment from others. [Footnote 18: Plato, Republic, ii. p. 364 A. [Greek: pa/ntes e)x e(no\s sto/matos u(mnou=sin], &c. Also p. 366 D.] [Side-note: He represents the motives to it, as arising from the internal happiness of the just agents.] The Platonic theory, or something substantially equivalent to it under various forms of words, has been ever since upheld by various ethical theorists, from the time of Plato downward.[19] Every one would be glad if it could be made out as true: Glaukon and Adeimantus are already enlisted in its favour, and only demand from Sokrates a decent justification for their belief. Moreover, those who deny its truth incur the reproach of being deficient in love of virtue or in hatred of vice. What is still more remarkable--Plato has been complimented as if his theory had been the first antithesis to what is called the "selfish theory of morals"--a compliment which is certainly noway merited: for Plato's theory is essentially self-regarding.[20] He does not indeed lay his main stress on the retribution and punishments which follow injustice, because he represents injustice as being itself a state of misery to the unjust agent: nor upon the rewards attached to justice, because he represents justice itself as a state of intrinsic happiness to the just agent. Nevertheless the motive to performance of justice, and to avoidance of injustice, is derived in his theory (as it is in what is called the selfish theory) entirely from the happiness or misery of the agent himself. The just man is not called upon for any self-denial or self-sacrifice, since by the mere fact of being just, he acquires a large amount of happiness: it is the unjust man who, from ignorance or perversion, sacrifices that happiness which just behaviour would have ensured to him. Thus the Platonic theory is