The Republic is one of the finest examples of a Platonic dialog. The subject matter discussed therein is difficult to summarize, at best. Covering subjects such as politics, the fine arts, education, it is no wonder so many have written volumes analyzing its various aspects. However, the driving force behind the many discussions is pursuit of the answer to the simple, yet evasive question, "What is justice?"

The heart of the debate on justice begins when, for a "fine", the Sophist Thrasymachus offers his definition of justice as, " . . . nothing other than the advantage of the stronger." He elaborates upon this simple definition by the example that the "good" man never gains any advantage on the "bad" man. Conversely, the man willing to lie, cheat, and do whatever in his power to achieve success, will always outdo the good man.

He supports his claim by stating a tyrant (ruler), in all his power, makes the laws in his own best interest; what is right for the subjects, the weaker party, is obedience to those laws. Thrasymachus states that people live "good" lives only because they are weak and afraid of doing otherwise. The strong and unjust man altogether leads a much fuller and happier life. In short, the tyrant's life is by far the best. Finding this conclusion lacking and disagreeable, Socrates attempts to prove Thrasymachus wrong by showing the just man is a happier man.

Socrates attacks Thrasymachus' position on three counts. He challenges 1) The claim the unjust man is more intelligent and has more knowledge than the just man; 2) The claim that injustice is the source of strength; 3) The claim that injustice brings happiness.

Drawing a comparison with other crafts and professions, Socrates begins his refute of the first claim. He notes it is almost always the ignorant which try to outdo the expert. An expert will recognize those better than himself and will choose not to compete, whereas the ignorant will still try to exceed illustrates Socrates. According to Thrasymachus, the unjust man tries to outdo everyone. Hence, Socrates concludes the unjust must be more ignorant than the just.

To illustrate the shortcoming in the second claim, Socrates points out among thieves and murderers there must be justice in their relations with one another. If this were not true and they were wholly unjust, they would not trust anyone and be incapable of working together, Socrates notes. By showing complete injustice is chaos and disunity, not a source of strength, Socrates shows the second claim to be false.