And there is no other cause of all this except the origin of this entire argument, directed by Glaucon and myself towards you, Socrates, to make the case that; “come on my wonderful man, of all of you who claim to be champions of justice, beginning with the earliest heroes whose utterances are still with us, right down to human beings, today, no one, so far, has censured injustice, or praised justice on any other basis than reputation, esteem, and the advantages that derive from them. And no one, so far, either in poetry or in ordinary language, has described in a sufficiently detailed argument, what each does, itself, by its own power, when present in the soul of its possessors, unknown to gods and to men; an argument whereby injustice is the worst of all the evils that any soul can have within herself, while justice is the greatest good. For if you had all described it in these terms, and convinced us of this from our earliest years, we would not have been acting as one another’s guardians, for fear we might behave unjustly, but each of us would, himself, be his own guardian, for fear that by acting unjustly, he would have to live with the worst evil of all.”
Republic II. 366d – 367a