The REPUBLIC starts with the question--what is JUSTICE? and, in answering it, provides the scheme of a model Republic. Book I. is a Sokratic colloquy, where one speaker, on being interrogated, defines Justice as 'rendering to every man his due,' and afterwards amends it to 'doing good to friends, evil to enemies.' Another gives 'the right of the strongest.' A third maintains that Injustice by itself is profitable to the doer; but, as it is an evil to society in general, men make laws against it and punish it; in consequence of which, Justice is the more profitable. Sokrates, in opposition, undertakes to prove that Justice is good in itself, ensuring the happiness of the doer by its intrinsic effect on his mind; and irrespective of exemption from the penalties of injustice. He reaches this result by assimilating an individual to a state. Justice is shown to be good in the entire city, and by analogy it is also good in the individual. He accordingly proceeds to construct his ideal commonwealth. In the course of this construction many ethical views crop out. The state must prescribe the religious belief, and allow no compositions at variance with it. The gods must always be set forth as the causes of good; they must never be represented as the authors of evil, nor as practising deceit. Neither is it to be allowed to represent men as unjust, yet happy; or just, and yet miserable. The poetic representation of bad characters is also forbidden. The musical training is to be adapted for disposing the mind to the perception of Beauty, whence it becomes qualified to recognize the other virtues. Useful fictions are to be diffused, without regard to truth. This pious fraud is openly recommended by Plato. The division of the human mind into (1) REASON or Intelligence; (2) ENERGY, Courage, Spirit, or the Military Virtue; and (3) Many-headed APPETITE, all in mutual counter-play--is transferred to the State, each of the three parts being represented by one of the political orders or divisions of the community. The happiness of the man and the happiness of the commonwealth are attained in the same way, namely, by realizing the four virtues--Wisdom, Courage, Temperance, Justice; with this condition, that Wisdom, or Reason, is sought only in the Ruling caste, the Elders; Courage, or Energy, only in the second caste, the Soldiers or Guardians; while Temperance and Justice (meaning almost the same thing) must inhere alike in all the three classes, and be the only thing expected in the third, the Working Multitude.