To fulfil the main task of describing justice in the individual person, Plato's Republic also describes justice in a state, and sketches an ideal state embodying justice. In doing this Plato answers some questions raised by Socrates. Though Socrates was suspected of disloyalty to the Athenian democracy, he says he prefers its laws to the less democratic laws of Sparta, Boeotia, and Megara. On the other hand, he attacks the democratic system for its conscious indifference to moral and political knowledge. He denounces democracy as a system that both flatters and moulds the impressionable and irrational impulses of the public, with no concern for people's real interests.

Socrates does not argue for one form of government over another. He does not formulate the ethical criteria for judging a government or a political system. Though he lived through civil war and constitutional change, he does not try to explain them, or to show how they can be avoided. Plato takes up these questions. The Republic argues that the right sort of state cannot exist unless philosophers rule it. Plato's argument for this intentionally paradoxical view exposes his main moral and political assumptions.

He assumes that the properly ordered state promotes the good of all its members, and that actual states are defective to the extent that they fall short of this aim. They all fall short of it because, as Thucydides shows, the pursuit of security, wealth, honour, and power produces conflict. When groups and classes in a city regard their interests as antagonistic, they really no longer constitute one city. In Plato's view, 'Every city, of whatever size, is really two cities at war with each other--the city of the poor and the city of the rich.' For Plato, this class struggle is the source of the political conflict between partisans of oligarchy and of democracy.

Some political moderates might suggest that the current aims of the rich and the poor are reconcilable; but Plato rejects this attempt to dissolve class conflicts. People think their good consists in the achievement of fame, honour, wealth, and power; for these are the 'contested' goods that people fight over. In Plato's view, if the opposing sides are right about what their interest consists in, then their interests are irreconcilable. In that case, as Thrasymachus says, principles of justice simply express the advantage of the politically dominant class, and the disadvantage of the others. Democracy satisfies the appetites of the masses, and its leaders have to gratify the popular tastes and desires. Government becomes mere flattery or pandering, resting on techniques of persuasion and manipulation. The technique Plato attacks is rhetoric; but had he known the techniques of advertising, promotion, and public relations practised in modern political propaganda, he would have found his charges confirmed beyond his worst fears. And if democracy is bad, other forms of government are no better; they gratify the equally mistaken desires of fewer people.

The Republic argues that a person's good requires justice and the other virtues. These are not contested goods, since we can pursue them as much as we want to without conflict; and in so far as we need the other goods, just people can distribute them without insoluble conflicts. To avoid class conflicts, therefore, a city must be ruled in the common interest by people who know how to achieve it. Since most people do not know what their own interest is, or what will promote the common good, they should not be rulers. The people with the necessary knowledge are the philosophers who know the Forms; hence they must rule the ideal state.

Since the rulers must use their knowledge correctly, for the common good, Plato strains to make them morally incorruptible. They have no private property or nuclear families to divert them from the common interest. Their early education encourages concern for the common interest. Their philosophical education cultivates love of the Forms, and a resulting desire to embody them in the institutions and practices of the state. To be qualified to rule, the people with the right natural abilities need many years of education, for which they are selected in childhood (most, but not all, from the children of the ruling class). Since Plato thinks the relevant natural abilities are found in women as well as men, he expects to recruit women as philosopher-rulers as well. Women rulers are an outrageously paradoxical result--as it would seem to most Greeks--of Plato's single-minded concern for the formation of a suitably qualified ruling class.

The 'lower' classes, of soldiers and productive workers, are educated far enough to appreciate the benefits they gain from the rule of the philosophers, without wanting to interfere with them. Since they do not know their own real interests, they cannot be ruled by their own reason; but they will come closest to psychic justice if they are entirely subject to the reason of the philosophers.

Plato regards other constitutions as the products of mistaken conceptions of the good, and of disordered relations between the parts of the soul, resulting in disordered relations between parts of the state. His criticisms do not imply that he ever wanted or planned to overthrow the Athenian democracy. Even if, in the right conditions, the rule of philosophers is preferable, still democracy might be the best in imperfect conditions and for imperfect people. If there are no philosopher-rulers available, or if most people are unwilling to accept the rule of philosophers, it might be better to accept a democracy than to overthrow it. Plato does not commit himself to the view that a less democratic regime is always preferable to a more democratic. Though he is a severe critic of democracy, he is not necessarily a supporter of oligarchy. . .