GAIVS NOSTER—Our Gaius:
The Jack of Roman Law
(ca. 110-180 A.D.)
“All our law is about persons, things, or actions.” —GAIUS, INSTITUTES I.II.8
Introduction: Gaius the "Jack" of Roman Law
If ever a man has been identified with his work it is Gaius, the great Roman jurist. Little is known of Gaius outside his one extant work, The Institutes, a text dating from about 160 A.D. that was used to introduce Roman law students to the world of law.1 Even his full name escaped history—the very common Roman name Gaius being only his personal name or praenomen.2 His name is so common that it frustrates historians, who complain that it “is hardly better than no name.”3 He may as well be called the "Jack" of Roman Law. And yet, though his name be common by the standards of Rome, “mystery surrounds his name” all the same.4 Virtually unmentioned by his contemporaries and the jurists of the next two centuries,5 Gaius returns posthumously with a vengeance in the 5th century, when the Law of Citations jointly promulgated by emperors Theodosius II and Valentinian III in 426 A.D. regards him as one of five jurists of eminent authority. So by a process not fully understood, Gaius rose from a relative unknown to the height of legal apotheosis—equal to the venerable greats Papinian, Ulpian, Paul, and Modestinus. Gaius was the source of Justinian’s Institutes and a large contributor to Justinian’s Digest, and through those he was grafted into the stock of Western Law. There are certain contributions to the law—Gaianisms, as it were—that we use today, most notably, perhaps, the distinction between substantive law and procedure, the division between contract and tort, and the distinction between actions in rem and in personam.
Historical Importance of Gaius: The Finding of His Institutes
None of the works of Gaius were known to have survived in their original text, until by happenstance in 1816 a palimpsest was found in the Chapter Library of the Palazzo dei Canonici by the German historian Barthold Georg Niebuhr.[^[+Tellegen-Couperus, 100-01; Seagle, 57. A palimpsest is a manuscript the surface of which was scraped of its original text so that it could be overwritten with different text. 
Gaius, U.S. House of Representatives
Because the method of erasing the original text was not always fully complete, the original texts can often be recreated through chemical means.+]^] That manuscript contained an erased 5th century text of Gaius’s famed Institutes covered by the text of St. Jerome’s epistles. Through chemical means the 5th century text of Gaius’s first century Institutes was brought to contemporary light and the eyes of the scholars. Because the text of the Institutes of Gaius represents the only work by a classical jurist that has survived time in nearly complete form, Gaius also has a preeminent place with the historians of Roman law interested in the period of the Principate (27 B.C. to 284 A.D.).6 For all his importance, however, it remains almost unexaggeratedly true: “All we know about Gaius as a person is that he lived in the second half of the second century,” as Tellegen-Couperus states.7 It is perhaps this historical anomaly—historical dearth and historical fame—that gives rise to the fertile theories surrounding Gaius. “No Roman lawyer,” Obrad Stanojević states, “has inspired so many controversial hypotheses.”8 However all that may be, his idealized profile—in life’s prime, confident, stolid, with squared jaw and Roman aquiline nose—decorates the chamber of the U. S. House of Representatives, one of only four Roman jurists chosen for that honor and one of the twenty-three great lawgivers of every time and place selected by the chambers’ planners.9 And so for both his contribution to the law and his accidental contribution to legal history, this uncommon man with a common name must be considered one of Law’s Greats. William Seagle captured both Gaius’s importance and the little known of him when he concluded, “[t]o men of law he is what Shakespeare has been to men of letters.”10 He also captured the importance of the Institutes of Gaius in the education of students of the law when he compared him to Blackstone: “The Roman law had its Gaius; the common law was bound to have its Blackstone.”11
Gaius: The “Peripatetic Professor”
Gaius was born, probably in Rome, somewhere circa 110 A.D. It is likely that he studied law in the Sabinian school under Aburnius Valero, and possibly Tuscianus.12 From 130 until his death, Gaius taught Roman law students the law. Teaching first at a Sabinian school in Rome, Gaius, the “peripatetic professor” with republican leanings, appears to have left the capital when the emperor Hadrian began his efforts to control the legal profession.13 He traveled and temporarily settled in the provincial towns of Dyrrachium, then Troas, finally settling in Beirut, perhaps associating himself with what was to become the famous law school of Beirut.14 He appears to have been familiar with Socratic “irony,” that feigned ignorance coupled with pointed questions calculated to educe truth from the student. Indeed, he may have been the first to use the “Socratic method” in teaching law,15 beating Harvard’s Professor Langdell, who introduced the Socratic Method in the 1870s in Harvard from whence it spread around the United States by more than a millennium and a half.
The Institutes, Law Students’ First Text, and Other Works
The Institutes—the book for which Gaius is most renowned—appears to be, or to have been informed by, his lecture notes.16 The discussion of law in the Institutes of Gaius indicates it was written between the years 130 and 180 A.D., which means Gaius flourished in the reigns of the emperors Hadrian (r. 117-138), Antoninus Pius (r. 138-161), Marcus Aurelius (r. 161-180), and the beginning of the reign of Commodus (r. 180-192).
As a book to educate law students, the Institutes of Gaius was perhaps the first book of its kind and appears to have been considered the best by the Romans themselves.17 When the emperor Justinian decided to reform the education of lawyers in the 6th century, he directed his favorite Tribonian and two law professors to update Gaius’s Institutes. Accordingly, the Institutes of Justinian relied very heavily on the Institutes of Gaius, adopting the format and, in many cases, the very words of Gaius.18 That perhaps is an understatement since as much as two-thirds of Justinian’s Institutes were taken from the Institutes of Gaius. Indeed, the emperor Justinian documents his and Roman society’s affection for Gaius if not their dependence, when he calls Gaius, Gaius noster, “our Gaius.”19 Professor Honoré points out the importance to Western jurisprudence of this choice: “Justinian used Gaius’ book as the basis of his own students’ book; and through Justinian Gaius has become the teacher of Europe.”20 “He has,” Honoré opines, “some claim at least to be thought of as the parens ac princeps of the profession of academic lawyer.”21
Though they have not survived except in fragments or title alone, Gaius wrote other works on the law, between 140 and 170 books. Some of these works are either quoted in Justinian’s Digest, and so are known to us only in part, or referred to in which case only their title is known.22 Gaius also wrote the first book about the law for the general public, the Res Cottidianae—sort of an early Roman “Law for Dummies.”23
Gaius’s Historicism, Conservatism, and Republican Leanings
The legal works of Gaius appear to have one overwhelming feature: a conservative bent which is reflected in an interest in the historical origins of Roman law. It is therefore ironic that a man who is virtually unknown to history as a person should find history so important in the study of law. From Gaius we learn, as Tony Honoré put it, “of the impropriety of approaching the study of law without considering its origins, and, as it were with unwashed hands.”24 To understand any law, including our own, we must wash our hands in the waters of history, sometimes even the waters of Greece and Rome.
Gaius’s conservative spirit stemmed from his attachment to the Sabinian school. Roman jurisprudence after the emperor Augustus was divided into two schools: the Sabinian—founded by the jurist Ateius Capito—and the Proculian—founded by the jurist Antistius Labeo.25 In the area of private law, the Sabinian school of jurisprudence advocated stricter adherence—to the degree practicable and reasonable—to inherited rules and customs; naturally, it resisted legal innovations and valued historical analysis, strict interpretation, continuity, and order.26 The competing Proculian school, on the other hand, stressed equity. As Tony Honoré observes, however, it was a matter of emphasis, and not the reliance on any absolute rule or doctrine, that distinguished the schools: “Though Sabinians make use of equity and Proculians of reason as a ground of decision, the weight of emphasis is the other way.”27
At the time of Gaius, the Sabinian school of thought appears to have shed its imperial bias, and was “conservative, rational, republican in at any rate a sentimental sense.”28 A devoted Sabinian would have bristled with discomfort when the emperor Hadrian sought to curb the independence of the legal bar by placing it under government control—in effect making the lawyer a civil servant.29 Accordingly, Gaius may have felt the need to leave Rome for the provinces in silent protest. This “politically incorrect” attitude of Gaius may also explain the dearth of contemporary references to him. His view on imperial control of the practice of law may have made him an undesirable authority to his contemporaries and successors who accepted imperial interference.
Gaius’s Contributions to Legal Science: Everyday Gaianisms
“Gaius made the decisive contribution to teaching methods, to pedagogic literature, and to the art of classification,”30 Honoré informs us. Gaius’s teaching methods and pedagogic literature have already been addressed. But his lasting contribution to legal science has not. Taught well by his Sabinian tutors, Gaius displayed a systematic genius and ability in developing classifications and definitions of legal concepts. It is in these areas that his contribution to the law has been enduring, both in the area of positive law and the philosophy of law.
In an original contribution, Gaius developed the “first system in the history of law,” dividing the law into persons, things, and actions (ad personas, res, actiones), thus distinguishing between substantive law and procedural law.31 Gaius was also father to the classic division between contract and tort (delict), although he recognized that that there were cases that appeared to share in features of both (i.e. quasi-contract, quasi-delict, or what we call contorts).32 It is Gaius who first distinguished between corporeal or tangible and incorporeal or intangible property.33 In his treatment on actions, Gaius differentiated between actions in personam and actions in rem, introducing into the law those terms which are familiar, though perhaps not happily, to any first year law student who has studied the cases of Pennoyer v. Neff, International Shoe, and Shaffer v. Heitner.34 In all these distinctions we still recall—though it be without proper acknowledgement and in historical ignorance—quod Gaius noster dixit, what our Gaius said.
Finally, influenced by Aristotle’s philosophical works, and perhaps also Stoic teachings, Gaius divided the law into “natural” or fundamental law based upon nature and reason, and “civil” or positive law based upon the will of the legislator, thus bequeathing, as a legal-philosophical patrimony of humanity, a tool with which to support, and, if need be, assess and to criticize, the positive law of the state.35 According to Tony Honoré, Gaius “mirrored Aristotle’s thought on the subject of law and justice with complete fidelity.”36
Our Gaius
Our Gaius. An innovator in the teaching of law. Perhaps the author of the first student textbook for the study of law. A contributor of fundamental distinctions of law that are still in common use today. These are uncommon contributions to the science of law by a man whose significance in the history of law and its development are belied by his common name and the little known of him. For a man as deeply devoted to law as he apparently was, he would probably be pleased that we remember his doctrines before we remember his name. There is a historical moral in all this: the law outlives, and is more important than, any one man, however much that one man may contribute to it.
Sources
Gordon, W. M. and Robinson, O.F., trans. The Institutes of Gaius. London: Duckworth, 2001.
Honoré, A.M. Gaius: A Biography. Oxford: Oxford University Press, 1962.
Seagle, William. Men of Law: From Hammurabi to Holmes, “Gaius.” New York: Macmillan Company, 1947, pp. 48-72.
Stanojević, Obrad. “Gaius and Pomponius: Notes on David Pugsley.” www.ulg.ac.be/vinitor/rida/1997/stanojevic.pdf.
Tellegen-Couperus, Olga. A Short History of Roman Law. London: Routledge, 1993, pp. 100-01, 104, 135, 137.
Endnotes
1 Roman jurists can be divided into iurisprudentes, who had some sort of imperial sanction or license under Augustus’ ius publicae respondendi ex auctoritate principis to issue legal opinions that bound judges, and iurisdocentes, who had no such sanction and can therefore be considered academics. Gaius was a iurisdocente. The precise nature of the ius respondendi is unknown. Stanojević, 341; Nicholas, 31-32; Seagle, 59; Honoré, xi. ⇑
2 By convention, Romans had three names, the praenomen (or given name), the nomen gentile (or tribe name), and one or two cognomen. Thus, e.g., Marcus (praenomen) Tullius (nomen gentile) Cicero (cognomen). ⇑
3 Honoré, xi. ⇑
4 Honoré, 12. ⇑
5 Pomponius, a contemporary of Gaius, refers to him in book 22 of his Commentary on Quintus Mucius—which is quoted in Justinian’s Digest—as “our learned friend Gaius.” D.45.3.39. Tony Honoré states that any discussion on Gaius’s life and work must begin with this one text of the Digest. Honoré, 1. ⇑
6 It is principally through Gaius’s Institutes that we know of the legis actio lawsuit, a form of lawsuit that was replaced by other procedures. ⇑
7 Tellegen-Couperus, 104. ⇑
8 Stanojević, 336. Some scholars deny his historicity, and suggest Gaius was the pseudonym of a learned woman or a pseudonym for the jurisdocent Pomponius. Some wave Gaius off as a “provincial,” a “third rank star in the field of roman jurisprudence,” or a plagiarist. Others, on the other hand, find Gaius to be one of the “pivots” of Western law and one of the greatest reformer of Roman law. Some regard his Institutes as “the most admirable work ever written” on the Roman ius civile, others as merely “rough lecture notes” of an unoriginal mind. See Stanojević, 336-38. ⇑
9 Thankfully rejected as a basis for the medallion were the whimsical musings of the German legal scholar Rudolf von Ihering (1818-92), who describes how the specter of Gaius rose before him through the cigar smoke in his study “as a strange figure of a man, tall, shriveled, slightly bow-legged, with freckled brow and the general air of a schoolmaster.” John Maxcy Zane, The Story of Law (Indianapolis: Liberty Fund, Inc., 1998), 151; see also Seagle, 61. ⇑
10 Seagle, 57. ⇑
11 Seagle, 205. ⇑
12 Honoré, 128-31. ⇑
13 Honoré, 130, 84-85. ⇑
14 Honoré, 84-85; 126. ⇑
15 Honoré, 110-12. ⇑
16 Honoré, 34. ⇑
17 Seagle, 57; Honoré, xii. ⇑
18 Inst., intro., 8. ⇑
19 C. Omnem, I; C. Imperatoriam, 6; J. Inst. 4.18.5. Honoré, 129. ⇑
20 Honoré, xii. ⇑
21 Honoré, xviii. ⇑
22 For example, Gaius’s On the Twelve Tables is a source for the description of the origins of Roman law in Justinian’s Digest. See D.1.2. In total, 4,494 lines of Gaius’s works were selected to be part of Justinian’s Digest. See Tony Honoré, “Word Frequency in the Study of Roman Law,” 30 CAMBRIDGE LAW JOURNAL 291 (1972) cited in Stanojević, 334 n. 5. Gaius’s work on Quintus Muncius and his Commentary on the Urban Edict are simply referred to and never quoted. Honoré, 4. Gaius’s works consist of: The Institutes (4 books); Commentary on the Urban Edict (Ad Edictum Praetoris Urbani) (appx. 60-70 books); Commentary on the Provincial Edict (Ad Edictum Praetoris Provinciale) (30 books); On Quintus Mucius (Ad Quintum Mucium) (appx. 20 books); On the Words of Obligations (De Verborum Obligationibus) (3 books); On Implied Trusts (De Tacitis Fideicommissis) (1 book); Ad SC Tertullianum (1 book); Ad SC Orfitianum (1 book); On Daily Things (Rerum Cottidianarum) (3 books); On Rules (Regularum) (appx. 1-3 books); On the Twelve Tables (Ad Legem XII Tabularum) (6 books); On Institutions (Institutionum) (4 books); On Types of Mortgages (De Formula Hypothecaria) (1 book); On Cases (De Casibus) (1 book); Dotalicion (1 book); On the Edict of the Aedile Curlium (Ad Edictum Aedilum Curlium) (2 books); On the Law of Julian and Papian (Ad Legem Iuliam et Papiam) (15 books). ⇑
23 Honoré, xii. The book was also known under the title Aurea. ⇑
24 Tony Honoré, Ulpian: Pioneer of Human Rights. (Oxford: Oxford University Press, 2002 (2nd ed.)), 84. See D.1.2 (Gaius, XII Tables, bk 1) (it is unfitting to deal with legal subjects “straight off with that subject matter, leaving out its beginnings, failing to trace its origin, not even, as I might say, giving their hands a preliminary wash.”). ⇑
25 The schools of thought are named after the subsequent leaders, Massurius Sabinus and Proculus. The schools were active for the first two centuries after the reign of Augustus, and thereafter appear to have become unimportant. Nicholas, 32-33. “Gaius was indeed the last jurist in whom the conflict of the schools was reflected. After him there was only one stream of Roman jurisprudence.” Seagle, 59. ⇑
26 In the area of constitutional law as distinguished from private, civil law, Labeo was a conservative, as he had strong attachment toward the republican form of government which was displaced by the Emperor Augustus. Labeo thus found himself a persona non grata in the modern Augustan regime. Capito, on the other hand, championed the new imperial order; but in the area of private law, he was conservative. Seagle, 55-56. The Proculian school maintained its founder’s legal tradition, but eventually abandoned its founder’s political tradition, becoming pro-imperial. Honoré, 37. “The Proculian [legal] tradition is summed up by Celsus filius: ius est ars boni et aequi.” Id. 38. ⇑
27 Honoré, 39. ⇑
28 Honoré, 38. ⇑
29 Honoré, xiii, 39. ⇑
30 Honoré, xviii. ⇑
31 Stanojević, 342; Inst. I.ii.8 (“All our law is about persons, things or actions”); Honoré, 113. ⇑
32 Stanojević, 343; Honoré, 98-104. ⇑
33 Seagle, 65. ⇑
34 Pennoyer v. Neff, 95 U.S. (5 Otto) 714, 24 L.Ed. 565 (1877); International Shoe Co. v. Washington, 326 U.S. 310, 66 S.Ct. 154, 90 L.Ed. 95 (1945); Shaffer v. Heitner, 433 U.S. 186, 97 S.Ct. 2569, 53 L.Ed.2d 683 (1977). ⇑
35 Honoré, 97, 106-08, 113. ⇑
36 Honoré, 110. ⇑
