Although large parts of the Republic are devoted to the description of an ideal state ruled by philosophers and its subsequent decline, the chief theme of the dialogue is justice. It is fairly clear that Plato does not introduce his fantastical political innovation, which Socrates describes as a city in speech, a model in heaven, for the purpose of practical implementation (592a-b). The vision of the ideal state is used rather to illustrate the main thesis of the dialogue that justice, understood traditionally as virtue and related to goodness, is the foundation of a good political order, and as such is in everyone’s interest. Justice, if rightly understood, Plato argues, is not to the exclusive advantage of any of the city’s factions, but is concerned with the common good of the whole political community, and is to the advantage of everyone. It provides the city with a sense of unity, and thus, is a basic condition for its health. “Injustice causes civil war, hatred, and fighting, while justice brings friendship and a sense of common purpose” (351d). In order to understand further what justice and political order are for Plato, it is useful to compare his political philosophy with the pre-philosophical insights of Solon, who is referred to in a few dialogues. Biographical information about Plato is fairly scarce. The fact that he was related through his mother to this famous Athenian legislator, statesman and poet, regarded as one of the “Seven Sages,” may be treated as merely incidental. On the other hand, taking into consideration that in Plato’s times education would have been passed on to children informally at home, it seems highly probable that Plato was not only well acquainted with the deeds and ideas of Solon, but that these deeply influenced him.
The essence of the constitutional reform which Solon made in 593 B.C.E., over one hundred and fifty years before Plato’s birth, when he became the Athenian leader, was the restoration of righteous order, eunomia. In the early part of the sixth century Athens was disturbed by a great tension between two parties: the poor and the rich, and stood at the brink of a fierce civil war. On the one hand, because of an economic crisis, many poorer Athenians were hopelessly falling into debt, and since their loans were often secured by their own persons, thousands of them were put into serfdom. On the other hand, lured by easy profits from loans, the rich stood firmly in defense of private property and their ancient privileges. The partisan strife, which seemed inevitable, would make Athens even more weak economically and defenseless before external enemies. Appointed as a mediator in this conflict, Solon enacted laws prohibiting loans on the security of the person. He lowered the rate of interest, ordered the cancellation of all debts, and gave freedom to serfs. He acted so moderately and impartially that he became unpopular with both parties. The rich felt hurt by the reform. The poor, unable to hold excess in check, demanded a complete redistribution of landed property and the dividing of it into equal shares. Nevertheless, despite these criticisms from both sides, Solon succeeded in gaining social peace. Further, by implementing new constitutional laws, he set up a “mighty shield against both parties and did not allow either to win an unjust victory” (Aristotle, The Athenian Constitution). He introduced a system of checks and balances which would not favor any side, but took into consideration legitimate interests of all social groups. In his position, he could easily have become the tyrant over the city, but he did not seek power for himself. After he completed his reform, he left Athens in order to see whether it would stand the test of time, and returned to his country only ten years later. Even though in 561 Pisistratus seized power and became the first in a succession of Athenian tyrants, and in 461 the democratic leader Ephialtes abolished the checks upon popular sovereignty, Solon’s reform provided the ancient Greeks with a model of both political leadership and order based on impartiality and fairness. Justice for Solon is not an arithmetical equality: giving equal shares to all alike irrespective of merit, which represents the democratic concept of distributive justice, but it is equity or fairness based on difference: giving shares proportionate to the merit of those who receive them. The same ideas of political order, leadership, and justice can be found in Plato’s dialogues.
For Plato, like for Solon, the starting point for the inquiry about the best political order is the fact of social diversity and conflicting interests, which involve the danger of civil strife. The political community consists of different parts or social classes, such as the noble, the rich, and the poor, each representing different values, interests, and claims to rule. This gives rise to the controversy of who should rule the community, and what is the best political system. In both the Republic and the Laws, Plato asserts not only that factionalism and civil war are the greatest dangers to the city, more dangerous even than war against external enemies, but also that peace obtained by the victory of one part and the destruction of its rivals is not to be preferred to social peace obtained through the friendship and cooperation of all the city’s parts (Republic 462a-b, Laws 628a-b). Peace for Plato is, unlike for Marxists and other radical thinkers, not a status quo notion, related to the interest of the privileged group, but a value that most people usually desire. He does not stand for war and the victory of one class, but for peace in social diversity. “The best is neither war nor faction – they are things we should pray to be spared from – but peace and mutual good will” (628c). Building on the pre-philosophical insights of Solon and his concept of balancing conflicting interests, in both the Republic and the Laws, Plato offers two different solutions to the same problem of social peace based on the equilibrium and harmonious union of different social classes. If in the Republic it is the main function of the political leadership of philosopher-rulers to make the civil strife cease, in the Laws this mediating function is taken over by laws. The best political order for Plato is that which promotes social peace in the environment of cooperation and friendship among different social groups, each benefiting from and each adding to the common good. The best form of government, which he advances in the Republic, is a philosophical aristocracy or monarchy, but that which he proposes in his last dialogue the Laws is a traditional polity: the mixed or composite constitution that reconciles different partisan interests and includes aristocratic, oligarchic, and democratic elements.