Reprint edition. Originally published: Berkeley: University of California Press, 1957. Through the lens of science, Kelsen proposes a dynamic theory of natural law, examines Platonic and Aristotelian doctrines of justice, the idea of justice as found in the holy scriptures, and defines justice as "...that social order under whose protection the search for truth can prosper. "My" justice, then, is the justice of freedom, the justice of peace, the justice of democracy-the justice of tolerance." (p. 24).