Rawls theory of social justice has been based on the social contract model that defines moral conceptions. He believes that justice is fairness and so when individuals work to produce social good, then there are enough goods for everyone. Thus according to Rawls in order to have distributive justice the concept of inequalities in distribution of the total wealth to all members of the society should not arise.
However when members of society compete for these goods, then the problem of distributive justice arises leading to the difference principle. The difference principle requires that the re-arrangement of the inequalities should be such that the outcome will lead to the greatest advantage to the least beneficiaries. This principle focuses on redistributing inequalities justly so as to benefit everyone. In other words, Rawls argues that individuals should make decisions as if the decisions made were going to affect themselves. (Samuel, 2003).
Rawls argues that principles that are used to govern the basic structure of justice in a society are those that would be selected by rational individuals in imaginary circumstances. According to Rawls, a society is well ordered when all its members are able to agree on the same principles that govern social justice as well as when the basic institutions of as society satisfy the principles and there is evidence that the principles are satisfied. This is why the assumption of the veil of ignorance and original position are used. According to Rawls these two assumptions were to help in driving the society to a more equal one.