John Rawls
This book of philosophy basically hosts the fight John Rawls vs. society. Rawls, who is the philosopher and is presenting his ideas, is changing the the typical values seen by society with his views. Because of this, he may be looked upon as a protagonist by some, while being seen as an antagonist by others. Describing that liberty and fairness are very close to the same thing, Rawls, uses thought experiments and rather planned methods of proving his point that the list of liberties he has would create a good society to live in.
Society
Society is the main factor at stake here - if Rawl's theories completely take hold, than society would be different. Even if this difference is not fundamental, society would still act as a dynamic character. As a whole, you have people for and against change in a society. Because Rawls is offering something not considered typical, there will always be those that go against him, and will deny others of their liberties. For this reason, society itself is the main antagonist, because the people in it prevent this somewhat-utopian model of events from happening - even though accepting it would be in their best interests.
