The main thesis of this paper is that justice is not a natural law that (re)establishes equilibrium and order in the universe, but a disposition enforced by a fighting will to render to every man his due in line with a regime of rights, powers, or immunities to use, enjoy and control some external goods. Inasmuch as there is no sense, feeling or instinct of justice, it is reasonable to assert that people regulate their conduct under the authority of a legislative authority according to certain ideas of justice, which they adopt and promote through a steady effort of knowledge and will. Critical analysis of the main types of justice − associative justice, punitive justice, corrective justice, restorative justice, functional justice, normative justice, commutative justice and distributive justice − from a liberal democratic perspective highlights the formal requirements of justice in different social arrangements and in relation to various aspects of personal and social life. Because it lacks a natural foundation of justice and people have strong interests in enforcing a certain idea of justice, public debates about justice entail a clash of militant wills. Debaters engage in a struggle for political hegemony trying to exclude from the public sphere the rival ideas about justice. In other words, all substantive debates about justice are carried out in an agonistic public sphere. The more civilized and reasonable the agonistic debates about justice are, the more likely the idea of justice is to fit the vital interests of individuals and society.