In Plato’s Republic, Socrates’ argues that justice cannot make people less just. In this essay, I will argue that his argument is not sound, because it depends on the questionable premise that the practice of a craft cannot produce its opposite. However, justice can sometimes make someone a worse person. Socrates claims that if you harm someone “they deteriorate in their human excellence” (p. 34). An excellence is a quality that is at the core of a species’ identity. Socrates states that the excellence of humans is justice; therefore, if you harm a person, they become less just. He goes on to say that you cannot make someone worse at a certain art or craft through the practice of it and gives the example that a musician cannot, “by practicing