Socrates then says that civic troubles in the state, in Greece generally, and indeed the world over, will probably never cease, and justice will never be fully realized until philosophers become the rulers or until present rulers and kings show themselves to be philosophers. In other words, philosophy and political power must be melded in order for the ideal state to be realized.
This remark, says Glaucon, is so revolutionary that it might cause more than one important citizen to seize the nearest weapon and attack Socrates. Glaucon demands an explanation of what Socrates has said, so Socrates defines what he means by philosopher.
Socrates then recapitulates and develops his analogy of the lover, showing that the lover is a lover, not of the part, but of the whole. So it is for the philosopher, the lover of wisdom and of all knowledge, one who is open-minded and always curious. Glaucon immediately objects; he argues that there exist plenty of people who know things and who display curiosity, but they are surely not philosophers. What about all the followers of Dionysus who flock to any festival site, no matter where; surely they seem to be curious about any new show or spectacle, but surely they are not philosophers. Socrates then defines the philosopher as one who loves the truth. At this point, Socrates must present Plato's theory about the nature of truth and knowledge.
