Social justice is the concept in which justice is achieved in every aspect of society, rather than the administration of law. It involves a greater degree of economic egalitarianism through progressive taxation, income redistribution, or even property redistribution, policies aimed toward achieving that which developmental economists refer to as equality of opportunity and equality of outcome. Social justice is described in much of John Rawls' writing. It is a part of Catholic social teaching and is one of the Four Pillars of the Green Party upheld by the worldwide green parties. Some tenets of social justice have been adopted by those on the left of the political spectrum. Social justice is also a concept that some use to describe the movement towards a socially just world. In this context, social justice is based on the concepts of human rights and equality.