Justice is the legal or philosophical theory by which fairness is administered. The concept of justice differs in every culture. An early theory of justice was set out by the Ancient Greek philosopher Plato in his work The Republic. Advocates of divine command theory argue that justice issues from God. In the 17th century, theorists like John Locke argued for the theory of natural law.Thinkers in the social contract tradition argued that justice is derived from the mutual agreement of everyone concerned. In the 19th century, utilitarian thinkers including John Stuart Mill argued that justice is what has the best consequences. Theories of distributive justice concern what is distributed, between whom they are to be distributed, and what is the proper distribution.

Egalitarians argued that justice can only exist within the coordinates of equality. John Rawls used a social contract argument to show that justice, and especially distributive justice, is a form of fairness. Property rights theorists (like Robert Nozick) take a deontological view of distributive justice and argue that property rights-based justice maximizes the overall wealth of an economic system.

Theories of retributive justice are concerned with punishment for wrongdoing. Restorative justice (also sometimes called “reparative justice”) is an approach to justice that focuses on restoring what is good, and necessarily focuses on the needs of victims and offenders.