John Rawls was an American liberal political philosopher at Harvard, most famous for writing A Theory of Justice, which attempted to tie social justice, political liberalism and social contract together in a unique way, defending what he describes as justice as fairness. His method of arriving his theory was called "original position", which he derived from the deontology of Immanuel Kant.
A Theory of Justice describes a theory as to the distribution of goods and resources in society - both material goods like food and housing, and more abstract goods like power, liberty and the like. Rawls posits what he describes as an original position - namely, a position apart from society, where self-interested, rational and equal people who are knowledgeable about human nature and society, but under a veil of ignorance regarding the place they will find themselves in society make decisions as to the fundamental principles on which society can be organised. The importance of the last constraint is to ensure neutrality - arguments, say, for a social welfare system are often seen as fallacious by those who are better off, while those who are not find the arguments against such a system to be equally fallacious - if both are placed in a position where they do not know whether they will be rich or poor, such arguments can be understood in a far more neutral way. This applies to all the future positions in society - race, religion, education, career, health and the such. Rawls describes the original position as follows:
In justice as fairness the original position of equality corresponds to the state of nature in the traditional theory of the social contrat. This original position is not, of course, thought of as an actual historical state of affairs, much less as a primitive condition of culture. It is understood as a purely hypothetical situation characterized so as to lead to a certain conception of justice. Among the essential features of this situation is that no one knows his place in society, his class position or social status, nor does any one know his fortune in the distribution of natural assets and abilities, his intelligence, strength, and the like. I shall even assume that the parties do not know their conceptions of the good or their special psychological propensities.[1]
Rawls states that those in the original position are "rational and mutually disinterested... not taking an interest in one another's interests"[2].
Rawls argues that people placed in such a situation would pick a number of principles. The first principle they would choose would be the principle of liberty, namely that each person in the society would have the maximum amount of liberty as is feasible with everybody else having the same. The second principle that most would choose would be the principle of difference, which describes how inequalities and differences could be distributed in such a society - that such inequalities would be distributed in such a way to aid the worst off in society, and that there is an equality of opportunity, so that anybody who wants to get to a position of inequality could do so if they applied themselves appropriately. An example may be that of doctors - a medical doctor may be paid significantly more than a manual laborer, but such a difference would be justified if the doctor aids those in a worse situation (which is quite likely in the case of a doctor), and the position of being a doctor is open to anyone who wants to try to become one.
Libertarian writers such as the philosopher Robert Nozick have been critical of Rawls' position, arguing that it is not possible to create a fair, patterned theory of the distribution of goods - arguing that the only measure which we can take regarding the distribution of goods that is consistent with a meaningful principle of liberty is one which judges distribution of goods fair simply on the basis of whether they were fairly acquired or transferred. Nozick uses a thought experiment based around the American basketball player Wilt Chamberlain - were Chamberlain, at the height of his fame with the Harlem Globetrotters, to charge spectators an extra premium on top of the ticket price to see a game, he would - under a Rawlsian or similarly patterned theory of justice - be acting in a fair manner. Should that matter? Nozick says no, and that it is a fair and just exchange.
Some multiculturalists and conservatives object to Rawls' assertion of universality in principles of justice, and instead emphasize the values of collective communities to form meaningful bonds of society.[3]