John Rawls's famous difference principle is capable of at least four distinct statements, each of which occurs in A Theory of Justice. According to what I shall term the Crude Principle it is a necessary and sufficient condition for the justice of an institutional scheme which expands social and economic inequality that, subject to the satisfaction of more weighty principles, it increases the level of advantage of the least advantaged. Expressing this principle Rawls writes that,Assuming the framework of institutions required (...) by equal liberty and fair equality of opportunity, the higher expectations of those better situated are just if and only if they work as part of a scheme which improves the expectations of the least advantaged members of society. The intuitive idea is that the social order is not to establish and secure the more attractive prospects of those better off unless doing so is to the advantage of those less fortunate. (shrink)