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 to the strong, who may act unjustly, so that the weak will "act justly" in serving their interests. He therefore affirms that justice is “stronger, freer and more masterful than justice” (Plato, Republic 344c). Plato begins to argue that injustice is never more profitable to a person than justice and Thrasymachus withdraws from the argument, granting Plato's response. Glaucon, however, is not satisfied and offers a challenge to Plato to prove that justice has 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 in which he asserts that his theory of justice, explained by three parts of the soul, proves the intrinsic value of justice and that a righteous life is preeminent. Finally, we will show that Plato's response succeeds in responding to Glaucon's challenge. Glaucon begins his argument against Plato by separating goods into three classes. The first class is made up of intrinsic goods that we welcome for ourselves, stripped of their consequences, such as happiness. The second class is the type of good that we love for its own sake as well as for its consequences, such as health and knowledge. The third class is an extrinsic good that we desire solely for its consequences, such as physical training and medical treatment. Plato believes that justice belongs to the second class of goods that we love because of itself and its consequences, while Glaucon suggests that it belongs to the third class of...... middle of paper . ..... act unfairly. Therefore, justice is seen as intrinsically valuable from the negative intrinsic value of injustice that has been demonstrated, as well as from the parts of the soul working properly together. Glaucon also wants Plato to show that a just life is better than an unjust life. It has been shown that when the soul is in harmony, it only acts rightly. It is in a person's best interest to have a healthy soul, one that is a righteous soul, so that he or she 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 rather than an unjust life. The conclusion I draw is that Plato's argument against the intrinsic value of injustice is sufficient to prove that the just life is superior, even though the unjust life may be more profitable.Works CitedPlato. Republic.