Justice
In its broadest sense, justice is the treatment of individuals fairly. According to the Stanford Encyclopedia of Philosophy, the most plausible candidate for a core definition comes from the Institutes of Justinian, a 6th-century codification of Roman law, where justice is defined as "the constant and perpetual will to render to each his due".
A society where justice has been achieved would be one in which individuals receive what they "deserve". The interpretation of what "deserve" means draws on a variety of fields and philosophical branches including ethics, rationality, law, religion, and fairness. The state may pursue justice by operating courts and enforcing their rulings.
History
Early Western theories of justice were developed in part by Ancient Greek philosophers such as Plato in his work The Republic, and Aristotle, in his Nicomachean Ethics and Politics. Modern-day Western notions of justice also have their roots in Christian theology, which largely follows the divine command theory, according to which God dictates morality and determines whether or not an action is seen as morally "good". This, in turn, determines justice.Western thinkers later advanced different theories about where the foundations of justice lie. In the 17th century, philosophers such as John Locke said justice derives from natural law. Jean-Jacques Rousseau was a prominent advocate of social contract theory, which holds that justice arises from a mutual agreement among members of society to be governed within a political system.
Modern frameworks include concepts such as distributive justice, utilitarianism, retributive justice and restorative justice.
In broad terms, distributive justice considers what is fair based on what goods are to be distributed, between whom they are to be distributed, and what the proper distribution is, utilitarian theories look forward to the future consequences of punishment, retributive theories look back to particular acts of wrongdoing and attempt to match them with appropriate punishment, and restorative theories look at the needs of victims and society and seek to repair the harms from wrongdoing. Theories of retributive justice say justice is served by punishing wrongdoers, whereas restorative justice is an approach to justice that focuses on the needs of victims and offenders.
Platonic justice
Justice, according to Plato, is about balance and harmony. It represents the right relationship between conflicting aspects within an individual or a community. He defines justice as everyone having and doing what they are responsible for or what belongs to them. In other words, a just person is someone who contributes to society according to their unique abilities and receives what is proportionate to their contribution. They are in the right place, always striving to do their best, and reciprocating what they receive fairly and equitably. This applies both at the individual level and at the organizational and societal levels.To illustrate these ideas, Plato describes a person as having three parts: reason, spirit, and desire. These parallel the three parts of a city in his philosophy, which he describes through the metaphor of a chariot: it functions effectively when the charioteer, representative of reason, successfully controls the two horses, symbolizing spirit and desire. Continuing on these themes, Plato theorizes that those who love wisdom, or philosophers, are the most ideal to govern because only they truly comprehend the nature of the good. Just like one would seek a doctor's expertise in matters of health rather than a farmer's, so should the city entrust its governance to someone knowledgeable about the good, rather than to politicians who might prioritize power over people's genuine needs. Socrates later used the parable of the ship to illustrate this point: the unjust city is like a ship in open ocean, crewed by a powerful but drunken captain, a group of untrustworthy advisors who try to manipulate the captain into giving them power over the ship's course, and a navigator, the latter of whom being the only one who knows how to get the ship to port.
Divinity and religious conceptions of justice
Advocates of divine command theory say that justice and the whole of morality is the authoritative command of God. Murder is wrong and must be punished, for instance, because God says it so. Some versions of the theory assert that God must be obeyed because of the nature of God's relationship with humanity, others assert that God must be obeyed because God is goodness itself, and thus doing God's command would be best for everyone.An early meditation on the divine command theory by Plato can be found in his dialogue, Euthyphro. Called the Euthyphro dilemma, it goes as follows: "Is what is morally good commanded by the gods because it is morally good, or is it morally good because it is commanded by the gods?" The implication is that if the latter is true, then justice is beyond mortal understanding; if the former is true, then morality exists independently from the gods and is therefore subject to the judgment of mortals. A response, popularized in two contexts by Immanuel Kant and C. S. Lewis, is that it is deductively valid to say that the existence of an objective morality implies the existence of God and vice versa.
Jewish, Christian, and Muslim theology traditionally follow that justice is a present, real, right, and specifically, governing concept, along with mercy, and that justice is ultimately derived from and held by God. According to the Bible, such institutions like the Mosaic Law were created by God to require the Israelites to live by and apply God's standards of justice.
The Hebrew Bible describes God as saying about the Judeo-Christian-Islamic patriarch Abraham: "No, for I have chosen him, that he may charge his children and his household after him to keep the way of the Lord by doing righteousness and justice;....". The Psalmist describes God as having "Righteousness and justice the foundation of throne;....".
The New Testament also describes God and Jesus Christ as having and displaying justice, often in comparison with God displaying and supporting mercy.
In Buddhist ethics, justice is not defined by individuals "receiving their due," as in some frameworks, but by the transformation of suffering for all sentient beings by addressing their ignorance and leading them to enlightenment with skillful actions rooted in generosity, virtue, and the development of universal goodwill and compassion. The concept of karma is understood not as a system of rewards and punishments, but as the continuation of actions, thoughts, and intentions that shape future experience within an interconnected web of life. Central to this view are the principles of all beings having Buddha nature, interbeing with a deep interdependence of all things, dependent origination, which states phenomena arise in dependence upon other phenomena, and non-duality, which challenges rigid distinctions between self and other, or right and wrong as fixed absolutes. Justice, from this perspective, does not consist of assigning blame or enforcing penalties, but of recognizing shared responsibility and cultivating compassion, mindfulness, and understanding that leads beings to enlightenment and a Buddhist form of restorative justice. The notion that individuals inherently deserve either suffering or reward is often critiqued as a misinterpretation of karma that reinforces ego and separation. Instead, Buddhist justice emphasizes developing compassion, reducing suffering for all sentient beings, and supporting conditions that can lead being to enlightenment. This restorative and transformative orientation contrasts with retributive models focused on individual deserts, offering a vision of justice rooted in collective liberation rather than reparation.
Natural law
Many have claimed that justice is a part of natural law. Natural law is a philosophical and legal theory that posits the existence of a set of inherent laws derived from nature and universal moral principles, which are discoverable through reason. In ethics, natural law theory asserts that certain rights and moral values are inherent in human nature and can be understood universally, independent of enacted laws or societal norms. In jurisprudence, natural law holds that there are objective legal standards based on morality that underlie and inform the creation, interpretation, and application of human-made laws. This contrasts with positive law, which emphasizes that laws are rules created by human authorities and are not necessarily connected to moral principles. Aquinas argues that because human beings have reason, and because reason is a spark of the divine, all human lives are sacred and of infinite value compared to any other created object, meaning everyone is fundamentally equal and bestowed with an intrinsic basic set of rights that no one can remove.Modern natural law theory was used in challenging the theory of the divine right of kings, and became an alternative justification for the establishment of a social contract, positive law, and government—and thus legal rights—in the form of classical republicanism. John Locke was a proponent of natural law, stressing its role in the justification of property rights and the right to revolution. Natural law is closely related to the concept of natural rights. Indeed, many philosophers, jurists and scholars use natural law synonymously with natural rights or natural justice; others distinguish between natural law and natural right. Some scholars note natural law has been used by philosophers in a different sense from those mentioned above, e.g. for the law of the strongest, which can be observed to hold among all members of the animal kingdom, or as the principle of self-preservation, inherent as an instinct in all living beings.