What is the theme in A Theory of Justice by John Rawls?

Individual liberties is a major theme in this book. In formulating his theory of justice as fairness, Rawls makes clear that the guaranteed freedom of each and every individual is essential to the establishment of a just society. He thus determines that liberty is the first priority in a hierarchy of principles defining justice; he places limitations on individual liberty only insofar as it impinges on the liberty of others. The first principle is stated as: "each person is to have an equal right to the most extensive scheme of equal basic liberties compatible with a similar scheme of liberties for others." In defining what he means by liberty, Rawls points out that there are different types of liberty and that some are more crucial to a just society than others.