Justice in Plato

What is justice? Why do men behave justly? Is it because they fear the consequences of injustice? Is it worthwhile to be just? Is justice a good thing in and of itself regardless of its rewards or punishments? Speaking through his teacher Socrates, Plato attempts to answer these questions in the Republic. In book I Thrasymachus, a rival of Socrates makes the claim that justice is nothing but the advantage of the stronger. It does not pay to be just because those who behave unjustly naturally gain power and become the rulers of society. Justice is what unjust rulers say is right through the rules that they make. It is injustice that is the source of happiness#. Plato sets out to disprove Thrasymachus' argument and provide an accurate definition of justice through which he will demonstrate that justice is good and desirable and it is in our best interests to adhere to it. Plato claims that there are two kinds of justice, individual and political. Since the city is larger than the individual it is easier to find justice at the political level and later inquire as to whether there is any similar concept to be found in the individual. To locate political justice he builds up a completely just city and observes where justice enters it.# Through the examination of this city Plato shows that both the ideal city and the just individual are balanced and structured through a principle of specialization, both are governed by reason brought forth by education, and justice is good in it of itself because of these reasons.

Instead of defining justice as a set of behavioural norms Plato identifies justice as a set of structural relationships among the parts of the whole.# Political justice is accomplished as harmony in a structured political body. Each individual is born with a natural role or skill that they must practice exclusively.# The ideal city consists of three main classes of people: producers who fulfill their necessary and unnecessary appetites and consist of the general population and labourers, auxiliaries who guard the city from external and internal conflict and are driven by spirit and passion, and rational guardians who rule the city.# Society is just when relations between these three classes are balanced. Each group must perform its appropriate function and only that function. Each must be in the correct position of power in relation to the others. Rulers must rule, auxiliaries must uphold the ruler's convictions and the producers must perform only the skills that nature granted them. No group can interfere in any other business. Rulers ought not produce and producers have no part in the political system of the polis.# Since this just city is set up the best way possible we can be sure it has certain virtues: wisdom to be found in the guardian class, courage to be found in the auxiliaries and moderation and justice which are spread across the entire city. Moderation is the agreement and acceptance of who ought to rule and justice is to be found in the principle of specialization, each person playing their natural role and only this role#

Plato has now defined justice in the political realm and moves on to show how it is mirrored on the individual level. He argues that the human soul consists of three parts, similar to those of the just city. The appetitive part of the soul desires material possessions and is ruled by appetites such as food, drink, sex and money, this part of the soul is similar to the class of producers in society.# The spirited part of the soul is analogous to the auxiliary class in the city and strives for honour and pride.# The part corresponding to the guardians of the polis is the rational part of the soul. It is driven by the love of knowledge and strives for truth.# Justice in the individual soul is that same as justice in society. It involves a correct balance in the power of the different parts, each fulfilling its proper role. In a just individual the rational part of the soul rules and the soul desires knowledge above all other appetites. The spirited part supports this rule and together these parts keep the appetitive part in line.# The entire soul aims at fulfilling the desires of the rational part. A person who's soul is set up in this way will naturally live a just life, just like a city based on principles of specialization will inherently be just. Instead of striving for honour or material possessions, which lead to greed, crime and other vices the rational soul is driven by the love of truth and is a healthy soul.# Plato shows that justice is not merely a set of actions or beliefs but is instead the result of the well-structured soul.

The guardians whose souls are naturally dominated by rationality and strive for wisdom are best able to understand what is good for the city and are therefore in the best position to govern the city. However, guardians are not produced perfectly by nature and their souls must be purified