In the Republic, justice is explained as a thing one ought to do and does ones best. Plato portrays that the ideal city consists of three social groups: workers, guardians and philosophers. Each of them hands certain natures that they cannot alter. Plato explains that attempting to do what people are not fitted to do by nature will only make them miserable. On the other hand, the tools people are handed at birth are not sufficient to guarantee that they will excel at the particular function nature assigns people. For that, education and training are necessary. Human natures must be nurtured if they are to bear fruit. Plato believes this to be as true of philosophy as it is of soldiering, farming, or weaving. "After the manner of poets, would seem to have spoken darkly of the nature of justice; for he really meant to say that justice is the giving to each man what is proper to him, and this he termed a debt" (Plato 1996).
Plato gives a special attention to the idea of justice and its role in the idea city. He state that those who rule do so by making and enforcing laws. Justice is obedience to those laws and injustice is disobedience to them. Since those who make the laws are not fools, and since they make laws that work to their own advantage, justice turns out to be the advantage of the strongest. "Two virtues remain to be discovered in the State--first, temperance, and then justice which is the end of our search" (Plato 1996). Plato describes that since most of people are not self-sufficient even in providing themselves with the requisites of physical survival, a role of the city is to produce them. The city incorporates a division of labor for the provision of food, shelter, and clothing. Plato underlines that people are more productive if they secialize in one thing rather than try to excel at many things, Socrates sets up the city as a community of interdependent shepherds, farmers, carpenters, weavers, cobblers, black smiths, traders, shopkeepers, and so forth.
Socrates agrees that the city he has described would be a truly healthy one and that to admit luxuries into it will. "Men of the governing class, are habituated to lead a life of luxury and idleness both of body and mind" (Plato 1996). On questioning poets about their expertise, Plato found that they in fact lacked the wisdom which they claimed, and were thus less wise than Socrates, who was at least aware of his own ignorance. He thus came to see that the wisdom which the oracle had ascribed to him consisted precisely in this awareness of his ignorance, and that he had a divine mission to show others that their own claims to substantive wisdom were unfounded. Plato underlines that this problem has deep roots and diverse causes: "there is an old quarrel between philosophy and poetry" (Plato 1996). Plato underlines that this enterprise of examining others (referred to as 'the Socratic elenchus'), which was the basis of his unpopularity and consequent misrepresentation, he later in