The modern scientific concept of Social Justice is no older than the month of May of 1931 — the date of the publication by Pius XI of his Encyclical Quadragesimo Anno. It is true that the term “Social Justice” had been coming into increasing use since the middle of the 19th century, but its meaning was fuzzy and ambiguous and amounted to little more than “social problems.” In Pius XI, the term is a scientific renaming of the age-old “legal justice,” which comes down to us across the centuries from the golden age of Greek Philosophy but which, through more than two millennia of mankind’s best efforts, failed to become anything more than a museum-piece, dutifully displayed at the beginning of any serious treatise on justice but then left completely undeveloped.
Ferree, William S.M.
"Saint Thomas and Social Justice,"
University of Dayton Review: Vol. 12:
1, Article 12.
Available at: https://ecommons.udayton.edu/udr/vol12/iss1/12