The Republic itself is nothing at the start of Plato's most famous and influential book. It does not exist. Not only does it not exist in actuality, but it does not exist in theory either. It must be built. It architect will be Socrates, the fictional persona Plato creates for himself. In the first episode Socrates encounters some acquaintances during the festival of Bendis. His reputation for good conversation already well-established, Socrates is approached by some dilettante philosopher acquaintances and drawn into a dialogue. The discussion quickly moves to justice thanks to Socrates. The other philosophers, including Thrasymachus, Polermarchus, Glaucon, and Adeimantus enthusiastically consent to such a worthy topic. However, it is unlikely at this point that any of these philosophers?save Socrates, of course?anticipates the ambition and enormity of their undertaking.
In Book I, Socrates entertains two distinct definitions of justice. The first is provided by Polermarchus, who suggests that justice is "doing good to your friends and harm to your enemies." The definition, which is a version of conventionally morality, is considered. Very soon though, its faults are clearly apparent. It is far to relative to serve as a formulation of the justice. Moreover, its individual terms are vulnerable; that is to say, how does one know who is a friend and who an enemy? And are not friends as much as enemies capable of evil? And when a friend acts wickedly, should he not be punished? And next, what does it mean that an action is good or bad? The perils of giving credence to false appearances is introduced early on as a major theme. It will be dealt with at length in the succeeding books. Thus surely an idea as noble as justice will not stand on such precarious ground. ...