Rawls is concerned with social justice. Specifically, he is concerned with a just distribution of goods (positive things), such as wealth, education and perhaps even emotional goods such as happiness and love. In other words, Rawls is concerned with how goods are spread out in a society. Currently, goods are distributed unfairly. Some individuals and nations have concentrated wealth, for example. Rawls thinks that a just distribution of goods must be fair. In order to decide what kind of distribution is fair, we must decide how to distribute goods without knowing how or if we will benefit from the way goods are distributed.
Rawls thinks that we can tell if a distribution is fair by using a thought experiment. Imagine that you are unaware of what position you will have in a society. This is what Rawls calls the original position, which is a hypothetical scenario. Rawls says that in the original position, you are behind a veil of ignorance. You do not know if you will be president or a pauper. You also don't know if you are young or old, rich or poor, married or single or talented or useless. You also don't know what race, religion or culture you belong to. Rawls thinks that if we don't know where we will be in a society, we will want to create a fair society where goods are distributed equally. Basically, the idea is that since you could possibly end up in the worst possible position, you would want to be treated fairly even as the lowest person in the hierarchy.
Two Principles. Rawls thinks that once behind the veil of ignorance, it will be rational to support two principles. First, we will support the equal liberty principle, which states that liberty for all people should be maximized. For example, everyone has the same freedom of speech so long as one person's freedom of speech does not interfere with another person's Second, it is rational to support the difference principle, which is about differences in distribution of goods. Specifically, the difference principle says that differences in how goods are distributed will be designed to benefit everyone in the society and will also be attached with positions or roles in the hierarchy that are available to everyone. For example, police may have additional power to use force and violence but this is because we think that this makes the whole society better. Also, this power is available to anyone who wants to apply to work with the police. Rawls thinks that the equal liberty principle is more basic and more important than the difference principle. Also, you cannot trade your liberties in order to gain goods. For example, you cannot sell your right to vote in order to gain wealth.
The basic idea is that such a method of designing a society will help to compensate for inequalities. For example, a person may be lucky and is born wealthy. However, this does not mean that this person deserves to be rich. Or someone might be born the son of a king but this does not mean that the king's son deserves to be royalty.
The equal liberty principle requires that one person's liberty will not interfere with another's. For example, my right to own a gun cannot interfere with my roommate's right to be safe. The difference principle requires not only that differences in distribution benefit everyone but also that special liberties or a wealth of goods must be earned and that such opportunities are available to everyone. For example, the president has special power. But the president only has special power because (1) it benefits our government and society if the president has special power and (2) the president earned this power through free elections in which anyone is free to run for president.
Objections to Rawls. First, the difference principle focuses only on the goods of each person individually rather than in comparison to other people. Specifically, the difference principle allows that as long as the lower class is benefited somehow, it is ok if the upper class benefits greatly. Second, the difference principle limits the benefits that talented or hard-working people can gain. If a person is smart, talented and hardworking, then why should there be limits to how much that person can earn? If that person works harder than other person, they should earn more!