John Rawls's theory of justice was a defining text for liberals in the 1970s. Rawls laid out an extensive and fundamental theory of "justice as fairness" which he developed into an extensive moral foundation for any modern society. He suggested that we think of this theory as a sort of proto-"constitution" -- a description of principles that any just society must satisfy, and that need to be embodied in the constitutions and laws of those societies. He expressed these ideas in A Theory of Justice: Original Edition in 1971 and in Justice as Fairness: A Restatement in 2001.
The fundamental idea of justice as fairness is that we can identify a set of principles that rational persons would accept as a fundamental contract -- if they lacked specific knowledge about what their position in society would eventually be. This is the condition that Rawls referred to as the "veil of ignorance" -- persons deliberate about principles of justice from behind the veil of ignorance so that they can't try to choose principles that would unfairly advantage them over others.
Rawls believes that two principles would be chosen in those circumstances: first, a liberty principle (the system of liberties should be maximum and equal); and second, a difference principle (social and economic inequalities in society should be arranged in such a way as to maximize the position of the least-well-off group in society; and all positions should be available according to fair principles of equality of opportunity).
These principles were commonly thought to point to a certain kind of society as being uniquely just: a liberal democracy with a redistributive welfare state. The principles of liberal democracy embody the liberty principle; and the redistributive welfare state is designed to establish the requirements of the difference principle. (Essentially this means that inequalities would reduced by transferring income and other goods to the least well off.)
But something very interesting is happening in the field of political philosophy today. Thanks to the work of political theorists like Martin O'Neill and Thad Williamson, philosophers are looking more closely at a concept that Rawls introduced but didn't develop very fully -- the idea of a property-owning democracy. O'Neill and Williamson's recent collection, Property-Owning Democracy: Rawls and Beyond, lays out some very interesting and detailed arguments about this concept. And it turns out that this concept has much more disruptive implications than the original theory was thought to do. Rawls's critique of capitalism seems much more radical than it originally appeared.
A property-owning democracy is one in which everyone has full and extensive liberties and in which there is a broad distribution of ownership of wealth. The idea is that political equality requires a degree of equality of ownership of wealth among citizens. Rawls wasn't exposed to the awesome power of super-pacs, but he could foresee the political implications of a heavy stratification and concentration of wealth within a democracy; and he concluded that this kind of stratification was fundamentally incompatible with the equal worth of political liberties for all citizens. So a just society will not tolerate this degree of inequality. Here is how Rawls puts it in Justice as Fairness:
Property-owning democracy avoids this, not by the redistribution of income to those with less at the end of each period, so to speak, but rather by ensuring the widespread ownership of assets and human capital (that is, education and trained skills) at the beginning of each period, all this against a background of fair equality of opportunity. The intent is not simply to assist those who lose out through accident or misfortune (although that must be done), but rather to put all citizens in a position to manage their own affairs on a footing of a suitable degree of social and economic equality. (139)
O'Neill and Williamson draw out the implications of this view of a just society by contrast with the realities of 2012:
The concentration of capital and the emergence of finance as a driving sector of capitalism has generated not only instability and crisis; it also has led to extraordinary political power for private financial interests, with banking interests taking a leading role in shaping not only policies immediately affecting that sector but economic (and thereby social) policy in general... The United States is now further than ever from realizing what Rawls termed the "fair value of the political liberties" -- that is, the core value of political equality. (5)
So in an unexpected way, Rawls's theory of justice seems to speak fairly directly to the political agenda of the Occupy Movement. The one percent simply should not have the amount of political voice it has in existing capitalism. And yet increasing stratification of wealth seems to be inherent in contemporary capitalism.