For other uses, see Justice (disambiguation).

Justice (French justice from Latin justitia, from justus "just") is a concept involving the system of consequences which naturally derives from any action or choice. In this, it is similar to many laws of physics; a prominent example of one is the Third of Sir Isaac Newton's Laws of Motion, which states that for every action there must be an equal and opposite reaction. Justice in some form or another affects all things in the universe; in the context of human actions, it means according individuals or groups what they actually deserve or merit, or are in some sense entitled to (classic Latin concept of unicuique suum). Justice is a particularly foundational concept within most systems of law, and draws highly upon established and well-regarded social traditions and values. From the perspective of pragmatism, it is the name for a fair result (thus, these views are not often representative of true justice, as justice and fairness are two entirely different topics). In most cases what one regards as "just" (not necessarily meaning what is just) is determined by consulting established and agreeable principles, employing logic, or, natural law In certain systems justice is determined, by consulting a majority, or in social contexts where religion dominates, justice may be thought to require deference to religious texts or to spiritual guidance, under a monarchy or authoritarian state the ruler/s determined what was just and doled out justice. All of these determinants of justice have at times delivered particularlly dark periods of history where justice was seen to be absent.

If a person lives under a certain set of laws in a country, concepts of "justice" are often simply deferential to the existing law —the issuing of punitive reprimands for violations may be referred to as "serving justice." In principle, this fits the general concept in that the individuals get what is supposedly due to them.