The concept of social justice implies that societies can be ranked from least to most moral, implicitly evaluating outcomes rather than processes or institutions. In practice, social justice is inherently Marxian, assuming it is morally preferable for wealth to be allocated in favor of virtuously productive workers, rather than to capitalists, who Marx defines as unproductive, exploitative parasites who contribute nothing to society, unjustly taking the lion’s share of what is produced. This purportedly moral dimension has enabled social justice to outlast other Marxian fallacies, such as as the labor theory of value.

Jesuit priest Msgr. Luigi Taparelli d’Azeglio (1793-1862) originated the term social justice in his 1883 magnum opus, A Theory of Natural Law. Though appeals to social justice can be distressingly vague, the concept invariably purports to offer a basis for the moral evaluation of society, approaches to social organization, individual choice and action and the like by dividing society into oppressors and oppressed. Feudal and socialist societies do exhibit this dichotomy, but note that under capitalism, all exchange is voluntary, so it becomes problematic to conflate wealth distribution or income inequality with social injustice. The ideal of social justice is equal distribution of wealth, income, power, privilege, and opportunity, whereas any inequality of income or wealth is automatically condemned, regardless of how it arose.