Although Socrates returns time and again to the concept of justice in his discourse on the perfect city-state, much of it seems off the original subject. One of his main points, however, is that goodness is doing what is best for the common, greater good rather than for individual happiness. There is a real sense in which his philosophy turns on the concepts of virtue, and his belief that ultimately virtue is its own reward. His first major point is that justice is an excellence of character. He then seeks agreement that no excellence is achieved through destructive means.
The function of justice is to improve human nature, which is inherently constructive. Therefore, at a minimum, justice is a form of goodness that cannot be involved in injuring someone’s character. Justice, in short, is a virtue, a human excellence. His next point is that acting in accordance with excellence brings happiness.
Then he ties excellence to one’s function. His examples are those of the senses — each sensory organ is excellent if it performs its function, as the eye sees, the ear hears. Therefore, the just person is a happy person is a person who performs his function. Since these are tied together, injustice can never exceed these virtues and so justice is stronger and is the good. However, Socrates does not stop there.
He goes on to examine the question of the nature of justice and the just life. He identifies the four of the Athenian virtues: wisdom, courage, moderation, and justice. For the bulk of the book, he looks at each virtue separately in terms of the perfect city state, but our focus is on justice. But he makes the point that justice, of the virtues, resides in man’s relations to other men, not just in man as an individual. Thus, it is an excellence in social organization and in the organization of the human soul. So justice is a virtue which must be connected to the function of efficient and healthful cooperation.
Justice is in one sense the greatest virtue for it is key to making the other virtues work together for the common good. If all the parts are to work together as a whole, each must have on function to excel at. Like the organs of the body, all contribute to the whole, but the eyes only see, the ears only hear. They do not share functions. Using this analogy, justice would be something like the moral mind which guides the body in its activities. Justice, then is the head, at the top of the hierarchy in social terms.
When the other three virtues work together in orderly fashion within the state, justice is produced. But for justice to be produced, it must come from everyone doing his assigned function under the excellent guidance of the ruling class. Despite his emphasis of justice as a function of the perfect state, Socrates also deals with justice as a personal virtue. He finds that there is a parallel between the organization of the state and the organization of the individual. Just as there are three virtues other than justice, Socrates finds three parts in the individual soul — sensation,