It offers detailed accounts of John Rawls's theory of justice as fairness; the alternative 'capabilities approach' developed by Nobel-prize winning economist Amartya Sen; the libertarian theories of Milton Friedman and Robert Nozick; the 'group-rights' based theory of Will Kymlicka; and Nancy Fraser's theory of participatory parity. The book also includes extensive discussions of the nature and purpose of political theorizing, and it asks whether theories of justice should take only social institutions as their subject, or should also comment on personal motivations and behaviour.