Amartya Sen helps the author to understand justice based on assessments of social realizations of what actually happens and not based on a perfect imaginative setting, a veil of ignorance for interests (John Rawls), a social contract or an ideal discourse situation. Justice has to do with capability opportunities and freedom of human life as a whole. The chapter argues that a theory of social choice has to consider as its validity condition the social realization of effective rule of Human Rights law.