Plato's Republic: Book I Synopsis

I recently picked up Plato's Republic and have been reading it very closely. This new series will document some of the thoughts I have to myself as I read. This post will be a synopsis of the first Book (essentially a chapter) in this work. 

 Book I begins the discussion of various questions revolving around justice. The fundamental questions presented in this first book will continue to be developed and discussed over the subsequent books. 

Those questions are: 

What is justice?

Why should we be just?

Book I opens with Socrates returning home from a religious festival with his friend Glaucon. On the way home, they meet Adeimantus and Polemarchus and detour to Polemarchus's home. They meet Polemarchus's father Cephalus and others when they arrive. At first, Socrates and Cephalus discuss the positive aspects of growing older, subsequently leading to a discussion about justice. Rather than come out right with his own definition, Socrates (Plato) engages with some beliefs about the nature of justice with his interlocuters. 

The first of which is with Cephalus, an elderly, wealthy man who believes that justice is about owning up to one's legal obligations and being honest. Socrates presents a counterexample, reasoning "If a friend lends you weapons while sane and asks for them back while insane, is it just to give them back, despite the obligation?". Thus, following rules is not always just. 

Cephalus makes his exit and Polemarchus offers his argument. He proposes that justice is giving what is owed to each person. He suggests that good should be done to friends and harm to enemies. While these arguments seem distinct, they both share the underlying assumption that each person should be given what they are due. Socrates counterargues by pointing out that justice is a virtue, which shouldn't harm anyone. The point Socrates makes next is one I thought of as well, which is that our judgment of who is a friend and an enemy is inherently flawed. Who is to say who is truly good or bad in this case? One's friend may be your enemy. 

The final argument is with Thrasymachus, a brutish, cynical Sophist who argues that justice is the advantage of the stronger. Those in power create laws that benefit themselves, the "just" person is forced to conform to them. Thrasymachus also claims that being just is not advantageous to the just person, as it only benefits others. He considers justice to be an unnatural convention that people adhere to and that justice should be ignored entirely. 

There is a considerable amount of conversation had here. Socrates refutes Thrasymachus' claim in three ways. First, Socrates has Thrasymachus agree that the view he supports views injustice as a virtue. Then, Socrates begins a line of reasoning that results in him concluding injustice cannot be virtuous because it is counteractive to wisdom. Finally, Socrates suggests that rulers have to be just to govern effectively, as injustice ultimately leads to disharmony and strife. 

The discussion ends in aporia, or a deadlock. In Plato's earlier dialogues, this usually marks the end of the discussion. Republic will move beyond this point, in which Socrates develops his own complex theory of what justice is and why it is desirable.