Socrates and Thrasymachus on Perfect and Imperfect Injustice

It is argued that the true definition of justice in Plato’s Republic appears not in Book IV but in Book I, where it is clear that justice is other-oriented or external rather than internal as per Book IV. Indeed, on Book IV’s definition, there is virtually no difference between justice and moderation. Considered here is a single argument between Socrates and Thrasymachus (351b-352d), in which Socrates contends that imperfect injustice is “stronger” than perfect. Rather than producing a just group, the justice between members of a group strengthens the injustice of a group whose external project is already unjust.