(written as Fairness)A general treatment of this topic from an economic point of view is under Equity. The foundation of what is probably the 20th century's most impressive contribution to political philosophy is a veil of ignorance. Rawls asks us to imagine ourselves to be the constructors of a just society, but being ignorant of our racial, social, and economic position within that society, on the grounds that these are irrelevant to questions of justice. From this 'original position', he asserts that a rational person would select only two basic principles of justice: first, the liberty principle: a schedule of basic rights, including liberty of conscience and movement, freedom of religion, which ought to be equally distributed and as complete as is consistent with each having the same; second, the difference principle: social and economic inequalities are justifiable only if they are to the advantage of the least advantaged person. Economists (and others) have struggled to fit health into Rawls' scheme. Rawls himself explicitly excluded health from the operation of the difference principle, arguing that it was a 'natural good' like 'intelligence'. Many economists, philosophers and other analysts think that Rawls was wrong to exclude health in this way. For example, Ronald Green wrote: '[A]ccess to healthcare like all basic primary goods, is important because it is instrumental to the pursuit of whatever other values we might have' (Green, 2001, p. 22).