Is something good because gods command it, or commanded because it is good?
Plato's dialogue Euthyphro poses a riddle still debated: is goodness commanded by the gods because it is good, or good merely because they command it? If the second, justice escapes human understanding; if the first, morality stands apart from the gods and people can judge it for themselves.
The most widely cited core definition of justice comes from Justinian's sixth-century Roman law code: the constant and perpetual will to give each person their due. Augustine warned that without justice, kingdoms are just large-scale gangs of criminals. Plato saw justice as balance, with each part of a person or city doing its proper work, pictured as a charioteer, reason, steering two horses, spirit and desire. In his Republic, the character Thrasymachus retorts cynically that justice is simply whatever serves the strong. Aristotle treated justice partly as virtue in general and partly as giving people what they deserve.
Other traditions frame it differently. Classical Confucian thought treated justice as a personal and public virtue, but one that did not include freedom or equality and sat outside the law, which aimed at order instead. Buddhist ethics centres not on receiving one's due but on relieving suffering for all beings, and treats karma as the ongoing effect of intentions instead of a scheme of rewards and punishments. Jewish, Christian and Muslim theology see justice as coming from God and paired with mercy; divine command theory holds that acts are right or wrong because God decrees them.
In the seventeenth century John Locke rooted justice in natural law and used it to defend property rights and even revolution, and natural law arguments helped undermine the divine right of kings. Rousseau instead championed the social contract, deriving justice from what members of society agree to, or would agree to under fair and unbiased conditions.
Modern debate sorts the question by purpose. Distributive justice asks who should receive which goods. Retributive justice looks back at a wrong and matches it with punishment, utilitarian theories look ahead to the effects of punishing, and restorative justice tries to repair harm by attending to both victims and offenders.
Source: Justice
