 The difference principle (the first part of the second principle, through (a)), addresses differences or inequalities in the distribution of the primary goods of income and wealth and powers and positions of office and responsibility. It basically requires that a society is to institute the economic system that would make the least advantaged class better off than they would be in any other feasible economic system, compatible with maintaining citizens equal basic liberties and fair equality of opportunity. Rawls defines “least advantaged” as those with the least share of the primary goods of income and wealth, and powers and positions of office. He also assumes the least advantaged are “fully cooperating” (JF 179), and “full and active participants in society” (CP, 259) who do their fair share in contributing to economic activity and the social product. Rawls thus regards “distributive shares” under the difference principle as the benefits that accrue to persons for doing their part in socially productive cooperation. The class of unskilled workers receiving minimum income satisfies his definition of least advantaged (TJ 98/84 rev.). Those who are able but unwilling to work “must somehow support themselves” (JF 179; cf. PL 182n). Disability payments to meet the needs of severely handicapped citizens who are permanently unable to work are not ascertained by reference to the difference principle for Rawls, but instead are to be determined by principles of assistance, which he leaves unspecified (PL 272n). As a principle for structuring basic economic institutions on grounds of reciprocity, the difference principle itself is not an appropriate principle for compensating mental and physical handicaps and other disabilities.