In Utilitarianism’s final chapter, Mill discusses “the idea of Justice” (155) in order to investigate whether justice represents “an ultimate criterion of conduct” (155) separate from happiness. For Mill, justice is primarily a “feeling” by which individuals judge experiences; to insist that justice represents something different from a desire for happiness is only possible when the fact that justice involves stronger feelings is acknowledged. These stronger feelings are all that provide justice with a “superior binding force” (156).

Mill examines the various meanings of justice to provide a definition of a just or unjust action. Mill argues that justice is often concerned with an individual’s “legal rights.” Actions are typically perceived as unjust whenever they “deprive any one of his personal liberty, his property, or any other thing which belongs to him by law” (156). Laws can also be considered unjust, which suggests that justice is less concerned with a violation of legal rights than it is with actions which “withhold from any person that to which he has a moral right” (157).

Mill also describes a number of situation which are connected to the notion of justice: for example, someone receiving “that (whether good or evil) which he deserves” (158-159); someone being partial, or “show[ing] favor or preference to one person over another” (158-159); and situations that involve the maintenance of equality between individuals.