Masurius Sabinus, also Massurius, was a Roman jurist who lived in the time of Tiberius (reigned 14–37 AD). Unlike most jurists of the time, he was not of senatorial rank and was admitted to the equestrian order only rather late in life, by virtue of his exceptional ability and imperial patronage. Masurius was the first person to give "state-certified opinions" (publice respondere), a privilege granted by the emperor which marked increasing imperial control over the judicial process after the end of the Roman Republic. Before the Principate of Augustus, the value of legal opinions was based on the expertise of those who gave them. The passage in the Digest of Justinian that discusses the granting of Masurius's authority is thus a pivotal point in the history of Roman law.
Masurius was a leader of the Sabiniani, a school or sect of legal thought in the 1st and 2nd centuries AD. He was succeeded by a line of jurists including Caelius Sabinus (consul 69 AD), C. Cassius Longinus (hence adherents of the school are also referred to as the Cassiani), Javolenus Priscus, and Salvius Julianus. C. Ateius Capito was the founder of the school. They were rivals to the Proculiani, named after Proculus, but despite many references in Gaius to their controversies, it is hard to disentangle consistent views for each. Gaius seems to have counted himself among the Sabinians. It may be that the Sabinian school were strict constructivists, while the Proculians exercised greater latitude in their arguments.
Masurius's principal work was a treatise on civil law (ius civile) in three volumes, which had extensive influence. Later jurists such as Ulpian wrote commentaries on his work, but preserved no excerpts.
- Juan Luis Vives, Early Writings (Brill, 1991), vol. 2, p. 87.
- O.F. Robinson, The Sources of Roman Law: Problems and Methods for Ancient Historians (Routledge, 1997), p. 8.
- Frederick Tomkins, The Institutes of Roman Law (London, 1867), p. 119.
- Digest 1.2.2,48–50. Alan Watson, The Digest of Justinian (University of Pennsylvania Press, 1998), n.p. online.
- Robinson, Sources of Roman Law, p. 8.
- Kaius Tuori, Ancient Roman Lawyers and Modern Legal Ideals: Studies on the Impact of Contemporary Concerns in the Interpretation of Ancient Roman Legal History" (Vittorio Klostermann, 2007), p. 75.
- James Muirhead, The Institutes of Gaius and Rules of Ulpian (Edinburgh, 1880), p. 586.
- Muirhead, Institutes, p. 586.
- Adolf Berger, Encyclopedic Dictionary of Roman Law (American Philosophical Society, 1953), p. 687. Gaius describes the Proculians as diversae scholae auctores, authorities whose school whose views were not consistent.
- Referring to them nostri praeceptores, "our teachers"; Muirhead, Institutes, p. 586.
- Tomkins, Institutes, p. 93.
- George Mousourakis, The Historical and Institutional Context of Roman Law (Ashgate, 2003), p. 296.
- Tomkins, Institutes, p. 119.