The work of the jurists

The granting of the ius publice respondendi to leading jurists by Augustus and his successors gave fresh impetus to legal science. The development of

jurisprudence in the early imperial period was precipitated also by the shift in emphasis from politics to administration, the broadening of the scope of Roman law through the gradual extension of the Roman citizenship in the provinces, the proliferation of legal transactions that resulted from the growth of trade and commerce, and the increased demand for legal education.

Like their predecessors of the republican period, the jurists of the Principate were engaged in various activities relating to the practice of law and the administration of justice. They gave opinions on questions of law to magistrates, imperial officials and judges (responderef, assisted citizens in formalising transactions and in drafting legal documents (cavere); advised litigants on the appropriate legal forms that had to be used by them in expressing their claims and on how to argue their cases in court,^[956] [957] and sometimes argued cases as advocates themselves (agere).ⁱ⁵ Furthermore, the jurists were engaged in the systematic exposition and teaching of the law.

An important aspect of the jurists' work was legal writing. The majority of juristic works were of a casuistic and practical nature: they grew out of legal practice and were written primarily for legal practitioners. It was only in their expository works, such as elementary textbooks and manuals, that the jurists adopted a more theoretical approach to the study of law. Depending upon their subject-matter and scope, the literary works of the classical jurists have been classified as follows:

(i)    Responsa, quaestiones, disputationes, epistulae - collections of opinions or replies delivered by jurists in exercise of the ius respondendi. Works of this type were written for practitioners and usually consisted of two parts: the first part contained juristic opinions concerned with the praetorian edict {ad edictuni), whilst the opinions included in the second part were connected with leges, senatus consulta and constitutiones principis. The adaptation of the original responsa for publication sometimes necessitated the further elaboration of the position adopted, especially when the opinions of other jurists were being argued against. Some of these works, especially the quaestiones and the disputationes, dealt with problems that arose out of actual cases discussed by the jurists in their capacity as teachers. Others, such as the epistulae, contained legal opinions given in writing by jurists to judicial magistrates, judges, private citizens or other jurists.

(ii)   Regulae, definitiones, sententiae - short statements of the law, originally issued in connection with specific cases, but later reformulated and expressed in the form of general rules. They were couched in easy to memorise terms as they were intended for the use of legal practitioners and, possibly, students.^[959]

(iii) General works on the ius civile. Some of these works became known as libri ad Sabinum or ex Sabino, because they were modelled on the relevant work of the famous jurist Massurius Sabinius {Libri III iuris civilis). Others were based on the earlier work of the jurist Q. Mucius Scaevola (first century BC) in which the materials were arranged in a way different from that adopted by Sabinus.

(iv)  Commentaries on the ius praetorium (or ius honorarium), referred to as libri ad edictum. In these works the edicts of the magistrates were examined and commented upon in connection with those aspects of the ius civile which they were aiming to supplement or correct.

(v)   Digesta - comprehensive treatises on the law dealing with both the ius civile and the ius honorarium.

(vi)  Institutiones or enchiridia - introductory or expository textbooks written primarily for beginners and students. A work of this type was the Institutes of Gaius.

The jurists also produced commentaries on individual leges or senstus consulta, commentaries on the works of earlier jurists and other kinds of monographs. The areas of the law, the legal institutions and the specific legislative enactments which were the subject-matter of the jurists' works were subjected to detailed analysis, usually backed by discussion of actual or hypothetical problems. Hypothetical problems, in particular, were often relied upon as a means of testing the limitations of a particular legal rule, principle or concept. Of the juristic literature of the classical period the Institutes of Gaius is the only work that has survived in its original form. Our knowledge of the rest is derived for the most part from fragments that have been included in the Digest of Justinian and other post- classical compilations of law.^[960]