Republic, Bk. I

The  Nature of Justice

(A) Cephalus and Polemarchus

(1) 'The definition of justice [is] speaking the truth and repaying what one has borrowed.'

But -- person who has gone crazy.

(2) 'it is just to give to each what is owed to him'

(3) 'to treat friends well and enemies badly is justice'

(a) kind of thief?

(b) real friends vs. believed friends

(c) by being unjust to others, one makes them worse

(B) Thrasymachus

(1) 'justice is nothing other than the advantage of the stronger'

i.e. 'the advantage of the established rule'

(a) problem of fallibility -- laws that are not to the advantage of the rulers

(2) 'A ruler, insofar as he is a ruler, never makes errors and unerringly decrees what is best for himself, and this his subject must do.'

(b) Craft (techne argument): 'no one in any position of rule, insofar as he is a ruler, seeks or orders what is advantageous to himself, but what is advantageous to his subjects.'

(3) The doer of injustice is happier than the doer of justice: 'injustice is more profitable than justice'