Ius

Ius or Jus (Latin, plural iura) in ancient Rome was a right to which a citizen (civis) was entitled by virtue of his citizenship (civitas). The iura were specified by laws, so ius sometimes meant law. As one went to the law courts to sue for one's rights, ius also meant justice and the place where justice was sought.

On the whole, the Romans valued their rights as the greatest good of Roman citizenship (Civitas Romana), as opposed to citizenship in other city-states under the jurisdiction of Rome but without Roman rights. Outsiders (peregrini) and freedmen (libertini) perforce used Roman lawyers to represent them in actions undertaken under the jurisdiction of Roman law. Representation was one of the civic obligations (munera) owed to the state by citizens. These munera (on which account the citizens were municipes) included military service as well as paying taxes, but specialized obligations might also be associated with functions of elected offices or assigned by the government, such as paying the cost of road or aqueduct maintenance. Some of these functions were highly lucrative, such as tax collecting, since the collector collected much more than he owed the government, but for the most part functionaries were appointed for their wealth and were expected to assume the costs as their munus. If they did not, they were tried and sometimes executed. Violation of the iura of other citizens, whether in office or out, was a serious matter, for which the punishment might be death.

Ius in ancient Roman law had two principal meanings, which are still reflected in French droit, German Recht, English right and Spanish derecho. Ferdinand Mackeldy, 19th-century jurist, analyzed them into two principles: ius is the law, a set of compulsory rules (Jus est norma agendi, "law is a rule of conduct"), which he called objective or positive law, and a set of possibilities to act (Jus est facultas agendi, "law is a license to act"), which he called subjective law, or duties.

Ius was defined by the jurists Publius Juventius Celsus and Julius Paulus Prudentissimus as the aequum et bonum, "the just and the fair", or justice. Jurisprudence was the art of bringing it about through application of the laws; thus ius was law in the abstract, as in the English usage of the term "the law". Iura were "the whole of laws" (iura populi Romani), not a list of all the laws, but the very principle of legality, which might be applied through this law or by the magistrates and lawyers of Rome through disputation in the law courts. Ius might be something less than the whole body of law when special fields were designated by an adjective, such as ius publicum, "public law," as opposed to private law.

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