Socrates thought that the discussion on justice had finished when he adequately answered Thrasymachus’argument, but Glaucon is not satisfied with the conclusion and adds his opinion to the conversation. Glaucon states that all goods can be separated into three classes: things people desire simply for its own sake, such as physical training and medical treatment; things people desire both for its own sake and because we get something out of it, such as happiness; the last class is the things we desire people like only because we get something out of it such as, knowledge and health. Glaucon wants Socrates to prove that justice falls in the third class because we want something out of it. Glaucon states that most people place justice in the first