Inequality Reexamined is a book by Amartya Sen (first published by Harvard University Press). In it Sen evaluates the different perspectives of the general notion of inequality, focusing mainly on his well known capability approach. The author argues that inequality is a central notion to every social theory that has stood on time. For only if this basic feature is satisfied can a social theory which advocates a set of social arrangements be plausible. Taken the inequality ingredient for granted, the crucial question becomes: inequality of what? Sen answers this basic question by advocating his preferred notion of equality which is based on the capability for functionings.
Functionings are of two kinds: elementary ones such as being in good health, nourished, sheltered and the more complex, social ones such as having self respect, taking part in the life of the community etc. Achievement of an individual is the set of these realized functionings. Whereas capability refers to the real options that someone has in order to pursue his subjective functionings who prefers most. Nevertheless inequalities related to class, gender, communities seem to hinder the extent of human freedom and thus decrease our capability to function. That is why a good society ought to mitigate such discrimination, promoting people's freedom which, according to Sen, is the most valuable element of a satisfactory life.