The Law of Citations (Lex citationum) was a Roman law created in AD 426 by the emperor Theodosius II. It was designed to help judges deal with vast amounts of jurist writings on a subject and thus to reach a decision. According to the legal historian Alan Watson, "This Law of Citations marks a low point of Roman jurisprudence, since [it declares] the correct opinion is to be found by counting heads, not by choosing the best solution."[1]
Authority was given to Ulpianus, Gaius, Paulus, Papinianus and Modestinus as they were some of the outstanding jurists of the classical period. Quotations used by these jurists were also given authority. If there was a conflict between the jurists, the majority view would prevail. In the event of an even number of views on each side, the view of Papinianus would be applied. If Papinianus expressed no opinion, the judge would then be free to use his own judgement.