Rawls belongs to the social contract tradition, although he takes a different view from that of previous thinkers. Specifically, Rawls develops what he claims are principles of justice through the use of an artificial device he calls the Original position in which everyone decides principles of justice from behind a veil of ignorance. This "veil" is one that essentially blinds people to all facts about themselves so they cannot tailor principles to their own advantage:
- "...no one knows his place in society, his class position or social status, nor does anyone 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. The principles of justice are chosen behind a veil of ignorance."
According to Rawls, ignorance of these details about oneself will lead to principles that are fair to all. If an individual does not know how he will end up in his own conceived society, he is likely not going to privilege any one class of people, but rather develop a scheme of justice that treats all fairly. In particular, Rawls claims that those in the Original Position would all adopt a maximin strategy which would maximise the prospects of the least well-off.
- "They are the principles that rational and free persons concerned to further their own interests would accept in an initial position of equality as defining the fundamentals of the terms of their association." (Rawls, p 11)
Rawls bases his Original Position on a "thin theory of the good" which he says "explains the rationality underlying choice of principles in the Original Position". A full theory of the good follows after we derive principles from the original position. Rawls claims that the parties in the original position would adopt two such principles, which would then govern the assignment of rights and duties and regulate the distribution of social and economic advantages across society. The difference principle permits inequalities in the distribution of goods only if those inequalities benefit the worst-off members of society. Rawls believes that this principle would be a rational choice for the representatives in the original position for the following reason: Each member of society has an equal claim on their society’s goods. Natural attributes should not affect this claim, so the basic right of any individual, before further considerations are taken into account, must be to an equal share in material wealth. What, then, could justify unequal distribution? Rawls argues that inequality is acceptable only if it is to the advantage of those who are worst-off.
The agreement that stems from the original position is both hypothetical and ahistorical. It is hypothetical in the sense that the principles to be derived are what the parties would, under certain legitimating conditions, agree to, not what they have agreed to. Rawls seeks to use an argument that the principles of justice are what would be agreed upon if people were in the hypothetical situation of the original position and that those principles have moral weight as a result of that. It is ahistorical in the sense that it is not supposed that the agreement has ever been, or indeed could ever have been, derived in the real world outside of carefully limited experimental exercises.