This volume explores ways of understanding equality and non-discrimination. Drawing on the timeless logic of realist philosophy, Catholic morality, and Catholic social teaching, the authors seek to provide intellectual clarity on many controversial questions. The contributors are lawyers, philosophers, and theologians who offer rich insights into the modern crisis of social thought on equality. They examine various global assaults on human life, marriage, the family, and the natural dignity of masculinity and femininity. They seek to uphold the essential foundations of reality for the attainment of the common good. The contributors attempt to move beyond a positivist mentality in order to evaluate the first principles of the natural law in which all human law is grounded. The various chapters evaluate developments and application of theories of equality and non-discrimination in the history of Western thought; in modern European practice; in contemporary inter-American practice; in the Asian setting; in the Middle East and North Africa; and in the Catholic canon law tradition. The authors strive to restore a universally valid conception of equality and non-discrimination as understood within the Catholic tradition.