In the first book of the Republic, Thrasymachus attacks Socrates' position that justice is an important good. He claims that 'injustice, if it is on a large enough scale, is stronger, freer, and more masterly than justice' (344c). In the course of arguing for this conclusion, Thrasymachus makes three central claims about justice.
- Justice is nothing but the advantage of the stronger (338c)
- Justice is obedience to laws (339b)
- Justice is nothing but the advantage of another (343c).
There is an obvious tension among these three claims. It is far from clear why somebody who follows legal regulations must always do what is in the interest of the (politically) stronger, or why these actions must serve the interests of others. Scholars have tried to resolve these tensions by emphasizing one of the three claims at the expense of the other two.