Final answer:
Socrates defines justice in 'The Republic' as the proper function of every part of the city or the individual, leading to a harmonious society and a fulfilled individual. Justice is valued not only for its beneficial outcomes but also for its intrinsic worth in helping achieve personal happiness and societal stability.
Step-by-step explanation:
In Plato's The Republic, Socrates' definition of justice is closely tied to the functioning of both the individual and the city. Justice, according to Socrates, is when each part of the society or individual performs its function properly without interfering with the roles of the others. Within the city, this manifests as functional specialization, where everyone has a role that is determined by their natural aptitude, which contributes to the overall harmony and success of the society. For the individual, justice is a virtue that leads to a balanced soul, allowing the person to act rightly and live a happy life.
Socrates' theory of justice states that justice for the individual is not only good for its consequences but also for its own sake. It allows the individual to achieve eudaimonia, or human flourishing, which is intrinsically valuable. This justice is reflected in a just city, where every citizen fulfills their societal duties and collectively maintains social harmony, pivotal for the city's survival and well-being.