R AWLS thinks that the fundamental idea in the concept of justice is fairness. And he regards the duty of fair play as a frimafacie duty, not an absolute duty: 'the duty of fair play stands beside other prima facie duties such as fidelity and gratitude as a basic moral notion; yet it is not to be confused with them' ('Justice as Fairness', Philosophical Review, 1958, p. 181). He says that justice represents 'but one of the many virtues of social institutions, for these may be antiquated, inefficient, degrading, or any number of other things, without being unjust. Justice is not to be confused with an all-inclusive vision of a good society .... There may well be inequalities which one considers are just, or at least not unjust, but which, nevertheless, one wishes on other grounds to do away with' (Philosophical Review, 1958, p. 165). Elsewhere he does imply that inequalities that are necessary in order to maximise the advantages of the worst off are just, and not merely not unjust (see his article 'Distributive Justice', in Philosophy, Politics and Society, Third Series, ed. by P. Laslett and W. G. Runciman). So Rawls allows that the claims of justice sometimes conflict with the claims of some other parts of morality. It can also be seen from the above paragraph (and from some of his other assertions) that when such conflicts take place, in some cases, according to Rawls, considerations of justice should (morally) be overridden by these other moral considerations, while in some other cases considerations of justice should (morally) get priority and not be overridden by these other moral considerations. It follows that Rawls allows for at least the following possibilities: