According to Wikipedia:
“Social justice generally refers to the idea of creating a society or institution that is based on the principles of equality and solidarity, that understands and values human rights, and that recognizes the dignity of every human being. The term and modern concept of “social justice” was coined by the Jesuit Luigi Taparelli in 1840 based on the teachings of St. Thomas Aquinas and given further exposure in 1848 by Antonio Rosmini-Serbati. The idea was elaborated by the moral theologian John A. Ryan, who initiated the concept of a living wage. Father Coughlin also used the term in his publications in the 1930s and the 1940s. It is a part of Catholic social teaching, the Episcopalians’ Social Gospel, and is one of the Four Pillars of the Green Party upheld by green parties worldwide. Social justice as a secular concept, distinct from religious teachings, emerged mainly in the late twentieth century, influenced primarily by philosopher John Rawls. Some tenets of social justice have been adopted by those on the left of the political spectrum.
Social justice is based on the concepts of human rights and equality and involves a greater degree of economic egalitarianism through progressive taxation, income redistribution, or even property redistribution. These policies aim to achieve what developmental economists refer to as more equality of opportunity than may currently exist in some societies, and to manufacture equality of outcome in cases where incidental inequalities appear in a procedurally just system. The Constitution of the International Labour Organization affirms that “universal and lasting peace can be established only if it is based upon social justice.” Furthermore, the Vienna Declaration and Programme of Action treats social justice as a purpose of the human rights education.”
“We must be the change we wish to see in the world” Gandhi