What is Rawls's basic argument?

Rawls’s basic argument is a distributive idea of justice. In his 1971 work, A Theory of Justice, Rawls identifies justice with a distributive paradigm that gives society the appearance of a distribution of obligations and benefits, advantages and disadvantages, roles and tasks. The idea of justice as a virtue of the institutions is related to a distributive function whose main rule is the maximin rule. “Maximin” is the contraction of maximum minimorum: inequalities are permitted when they maximize, or at least generally contribute to improving, the prospects of the least privileged in society (minimorum).
Let us take Rawls’s example of promising. It is contained in the same work, in the chapter “Promising and the Principle of Fairness.” Where does the binding nature of promising lie? How does the special claim of the promisee originate? Rawls identifies it through a contractual pattern. At a first level, if I say that I must perform an action because I promised to, we do not need further explanation; however, doubt seems to arise at a second level, the philosophical one. At this second stage, the understanding of promising demands an answer to the following question: where does the so called "normative power" of a promise—the power, that is, of the promisor to compel himself—stem from? Rawls’s argument is based upon the definition of a principle of fairness (p.342).

A person is under an obligation to do his part as specified by the rules of an institution whenever he has voluntarily accepted the benefits of the scheme or has taken advantage of the opportunities it offers to advance his interest, provided that this institution is just or fair.

There is a social practice of promising that creates social benefits. If you take part in this social practice, you are obliged (if the practice of promising defined by the rules is fair and just) by the principle of fairness to fulfill your promises. Rawls states that the principle of fidelity (which compels us to keep the promise) is the application of the principle of fairness to the social practice of promising. The so defined moral context is what generates the normative power of promising.
The core of Rawls’s argument is thus a conventional view of promises, where a cooperative policy, based on the hypothetical, ideal agreement that would be acknowledged by men if they were to state it by means of a contract, is necessary to create that assurance in men, without which society would not progress at all.
According to some critics, Rawls’s theory brings about an unavoidable formalism in justice, for the best outcome justice can lead to is a society in which reciprocal disinterest is the prevailing attitude. The acknowledgement of an authentic cohesion where anyone may feel (rather than be) in debt with each other is consequently ruled out.
Nonetheless, Rawls has the merit of having unveiled some of the most complex and disputable mechanisms of contemporary society, including the objectionable conditions of those least privileged.
FURTHER READING:
- Rawls, J.: A Theory of Justice, The Belknap Press of Harvard University Press, Cambridge, Massachusetts 1971.
- https://www.britannica.com/biography/John-Rawls