Plato's Republic focuses on a particular question: is it better to be just or unjust? Thrasymachus introduces this question in Book I by suggesting that justice is established as an advantage for the stronger, who can act unjustly, so that the weak “act justly” by serving his interests. Therefore, he states that justice is “stronger, freer, and more masterly than justice” (Plato, Republic 344c). Plato begins to argue that injustice is never more advantageous to a person than justice and Thrasymachus withdraws from the argument, accepting Plato's response. Glaucon, however, is not satisfied and proposes a challenge to Plato to demonstrate that justice has an intrinsic value and that living a just life is always superior. This article will explain Glaucon's challenge to Plato regarding the value of justice, followed by Plato's response arguing that his theory of justice, explained by the three parts of the soul, demonstrates the intrinsic value of justice and that a just life it is pre-eminent. Finally, it will be shown that Plato's response succeeds in meeting Glaucon's challenge. Glaucon begins his argument to Plato by separating goods into three classes. The first class is composed of the intrinsic goods that we embrace for ourselves, stripped of their consequences, such as happiness. The second class is the kind of good we enjoy for ourselves and its consequences, such as health and knowledge. Third class is an extrinsic good that we desire only for its consequences, such as physical preparation and medical care. Plato holds that justice belongs to the second class of goods that we like for its own sake and its consequences, while Glaucon suggests that it belongs to the third class of... middle of paper... acting unjustly. Therefore, justice is determined to be intrinsically valuable by the negative intrinsic value of the injustice that has been demonstrated, as well as by parts of the soul working together correctly. Glaucon also wants Plato to show that a just life is better than an unjust life. It has been proven that when the soul is in harmony, it acts only with justice. It is in a person's best interest to have a healthy soul, which is a righteous soul, so that the person can be truly happy. This means that by showing that justice has intrinsic value, one can also conclude that it is better to live a just life than an unjust life. The conclusion I have drawn is that Plato's argument against the intrinsic value of injustice is sufficient to demonstrate that the just life is superior, even if the unjust life may be more profitable. Works Cited Plato. Republic.