The Age of Science

The great flowering of Roman law occurred between the second half of the second century BC and the first quarter of the third century AD.¹⁰ The change from the pre-scientific stage was triggered by two factors: the development of a different type of legal procedure, known as the formulary system, a remedial framework which gave sharper definition to the basis of claims; and the emergence of a class of jurists who applied a more sophisticated type of reasoning to the law than had previously been the case.

In all probability the formulary system emerged in the third century BC as a substitute for the legis actio procedure to deal with cases involving foreigners who could not swear the necessary oaths, but after the lex Aebutia (about 140 BC) it could be freely used by Roman citizens.

The second factor triggering the change was the application of more sophisticated types of reasoning to the law, very possibly under Greek influence.

The best starting point for any study of the sources of Roman law in this period is the Institutes of Gaius, an introductory manual written in the middle of the second century AD and not superseded until the production of the Institutes of Justinian four centuries later. The Institutes begin with a list of the sources of law:

The laws [iura] of the Roman people consist of leges, plebi­scites, senatusconsulta, imperial constitutions, edicts of those possessing the right to issue them, and answers of the learned. 15

We can usefully sub-divide this into three types: legislative sources, procedural sources, and juristic sources.

Legislative Sources

Gaius launches into his treatment of the sources with leges and plebiscites:

A lex is a command and ordinance of the populus. A plebiscite is a command or ordinance of the plebs. The plebs differs from the populus in that the term populus designates all citizens including patricians, while the term plebs designates all citizens excepting patricians. Hence in former times the patricians used to maintain that they were not bound by plebiscites, these having been made without their authorization. But later a lex Hortensia was passed, which provided that plebiscites should bind the entire populus. Thereby plebiscites were equa­ted to leges.1⁶

That lex took pride of place is very revealing, in two ways — all the more so given the relatively small number of legislative enactments in Rome. First, it shows that Gaius’s conception of law (ius) had at its heart rules which had been consciously laid down after deliberation. Law was not principally something immanent, waiting to be discovered; it was some­thing that could be, and in its paradigm form was, created by human act. Secondly, it was the leges of the three representative comitia that came first, with plebiscites coming after them. Not only was their authority chronologically later, but Gaius’s language points to their being, in his eyes, a second-class form of legislation: it was only the lex Hortensia that had raised them up to the status of true leges. The reason for this is transparent in his text: leges were enacted by the whole of the citizenry, whereas plebiscites were enacted only by a subset of them - the plebeians. It was not just the fact that leges and plebiscites had been enacted in accordance with certain recognized procedures that was important, therefore, but that in their ideal form they articulated choices which had been made by the whole of the Roman people.

It is worth emphasizing just how few leges and plebiscites are referred to in Gaius’s text: a total of around 35 in his 4 books. Of these, just under half regulated wills, personal status, and family relations, and about the same number regulated legal procedure. In the field of private law (the relations between free individuals), there are only 8. Moreover, by the time at which he was writing, the creation of law by lex or plebiscite was completely moribund; however, this did not prevent their appearance as the primary source in his list:

After leges and plebiscites in Gaius’s list, there come senatusconsulta:

A senatusconsultum is a command and ordinance of the senate; it has the force of lex, though this has been questioned.¹⁷

Again we see the binding force expressed in terms of lex. It is not simply that senatusconsulta are binding on the Roman people, but that in this respect they are equivalent to lex itself.

The doubt expressed at the end of Gaius’s text demands some exploration. We may be sure that Gaius did not share it, since elsewhere in the Institutes he makes references to rules stemming from senatuscon­sulta without any qualification, but clearly there was at the time an element of ambiguity about their status. It seems clear that in the Republic the Senate, for all its political power, was not seen as having the ability to legislate for Rome (legislation for the provinces was a different matter). It could make proposals to other bodies in the strong expectation that they would be adopted, but no more than that. However, in the early Empire, we find resolutions of the Senate being referred to as such, even though effect was given to them by clauses in the praetor’s edict: the Augustan senatusconsultum Silianum, for example, or the senatusconsultum Macedonianum passed under Vespasian.

Gaius’s final legislative source is in many ways the most problematic:

An imperial constitution is what the emperor by decree, edict or letter ordains; it has never been doubted that this has the force of lex, seeing that the emperor himself receives his imperium [sovereign power] through a lex.²1

That imperial constitutions were binding could hardly have been denied in the middle of the second century, but there are two elements of Gaius’s statement which give grounds for pause. First, as with the other legislative sources he enumerates, their force is described by reference to lex, the ordinances of the whole of the Roman people. The belief that it is lex that represents the ideal source of law is unmis­takable.

Gaius enumerates three distinct forms of imperial constitution - decrees (decreta), edicts (edicta), and letters (epistulae). There was no magic in the ordering of the different forms; they simply reflect different ways in which imperial power might generate legal rules.

Imperial edicts were a type of legislation in its strictest form: rules deliberately introduced to make new law or amend the old.²⁴ Provincial governors and similar magistrates had the right to issue such edicts in the Republic, and the emperor, vested with magistral powers, was doing no more than exercising the same right. Most of the earliest imperial edicts of which we have evidence were of limited application, restricted either to particular localities or particular individuals or groups. There was nothing to prevent the making of edicts introducing general rules, such as that of AD 212 giving Roman citizenship to all free people in the Empire,²⁵ but it was not until the end of the third century that this practice became widespread. Analogous to these were mandata: administrative instructions to officials.

Decrees were rules derived from the decisions of the emperor sitting as a judge.²⁶ From the time of Augustus, the emperor might make decisions outside the normal course of legal procedure, by taking cognizance of a lawsuit; the procedure was therefore known as the cognitio extraordinaria. Although he would sit with an advisory consilium, it was the emperor who made the decisions. We have, for example, a report of his being on one occasion persuaded by the jurist Paul (a member of the consilium) to change his mind, and another of his following a view of Papinian contrary to the advice of Paul.²⁷ The decisions of the emperor were, of course, binding on the parties, but they might also go beyond this and allow the formulation of a general rule. Hadrian ruled, for example, that a child born to a woman eleven months after her husband’s death might be legitimate, and Marcus Aurelius that violence did not necessarily involve any wounding.²⁸ Around the start of the third century Paul collected three books of such decrees, extracts of which survive in Justinian’s Digest.

Gaius’s final category, letters (epistulae), is a composite term referring to all communications from the emperor.²⁹ Some of these were addressed to officials, but more important and apparently more numerous were those addressed to private individuals. These took the form of rescripts, answers to petitions (libelli), with the imperial response written below the request. Julius Caesar is known to have dealt with such petitions, and it is likely that the imperial practice was a continuation of this. By the reign of Tiberius at the latest these petitions might concern matters of law: Papinian cites a rescript of his on the subject of adultery by public officials.³⁰ The surviving evidence points to there having been a massive increase in the number of rescripts issued during the reign of Hadrian, probably associated with the increasing legalization of government at this time,³¹ after which they became an increasingly important source of law. The rescripts were always given in the name of the emperor, and there is strong evidence that until the end of the second century the emperor’s part in making them was not merely nominal, although he would pre­sumably have taken advice from members of his consilium. A text ofUlpian records a rescript of Marcus and Verus (and hence of the AD 160s) making reference to what they had learned from ‘those skilled in giving legal opinions’ and to discussion with the jurist Volusius Maecianus and others, leading ultimately to the emperors favouring the view of Julian and others over that of Proculus.³² From the start of the third century, however, the personal input of the emperor began to wane, as responsibility for the drafting of rescripts was delegated to jurists in the imperial service, in particular to the principal secretary a libellis.

While the first of Gaius’s categories of imperial constitutions was unequivocally legislative, the second and third were far more ambiguous. On the one hand they purported simply to apply or state the law as it was, not to create anything new, and the recourse they had to legal experts emphasizes that this was taken seriously. On the other hand, since they were determinations of the emperor they were by definition authoritative statements of the law which took effect just as if they were genuinely legislative acts. As if to underscore this, by the time of Hadrian and probably earlier, rescripts were copied and recorded in the imperial archives, where they were available for consultation and hence came to be integrated into the legal fabric; the fact that at the beginning of the third century Paul could collect three books of decrees suggests that they too were recorded in some way, even if they might not have been so easy to consult.

Procedural Sources

After describing the various types of legislation, Gaius turned to what we might regard as procedural sources, the edicts of those possessing the right to issue them:

The right of issuing edicts is possessed by magistrates of the Roman people. Very extensive law [ius] is contained in the edicts of the two praetors, the urban and the peregrine, whose jurisdiction is possessed in the provinces by the provincial governors; also in the edicts of the curule aediles, whose jurisdiction is possessed in the provinces of the Roman people by quaestors; no quaestors are sent to the provinces of Caesar, and consequently the aedilician edict is not published there.³³

We need not concern ourselves with the elements of provincial admin­istration, nor with the aedilician edict (although it was important, espe­cially for the regulation of sales in the market place), but should focus on the praetor’s edict.

As has been seen, from the third century BC the praetors had provided formulae structuring lawsuits.³⁴ These formulae were collected together in their edict by the first century BC, and constituted a catalogue of available civil law remedies and defences. Although change was still possible, the edict had ceased to be a creative force by the end of the Republic. A century and a half later Hadrian commissioned the leading jurist of the time, Julian, to produce a definitive text, after which no further changes were possible unless they were made by the emperor.³⁵

Gaius’s description of these procedural sources is telling: nowhere does he mirror his previous texts and say that they had the force of lex. Nor could he, since they did not create legal rules in the same way as leges, plebiscites, senatusconsulta, or imperial constitutions. They did not really create rules at all, but in so far as they constituted the categorical list of remedies and defences - most were articulations of custom or derived from legislation, while some had been invented by praetors them­selves³⁶ — it was impossible for lawyers to ignore them. In reality, a knowledge of the edict was far more fundamental than a knowledge of legislation. Its inclusion in Gaius’s list brings home the point that the separation between substantive law and procedure, explicit in his state­ment that all the law relates to persons, things, or actions,³⁷ is largely artificial, and that procedural law can have a direct effect on substantive legal rules.

The Jurists

The late second and early first centuries BC had seen the rise of a cadre of secular jurists, whose role, according to Cicero, was to know and advise on lex and custom.³⁸ In the early part of the Empire they developed a formidable expertise, with a range of techniques to identify what was the correct result to any legal question, so that at the time Gaius was writing a substantial part of Roman law would have been seen as jurists’ law.

Gaius’s brief description raises as many questions as it answers:

The answers of the learned are the decisions and opinions of those who are permitted to establish the laws. If the decisions of all of them agree, what they so hold has the force of lex, but if they disagree, the judge is free to follow whichever decision he pleases. This is declared by a rescript of the divine Hadrian.³⁹

The first point to note is that juristic opinion, provided it was unanimous, created a rule on a par with lex. This may seem surprising since jurists were not formally appointed in any way, and were no more than men who claimed to have the appropriate expertise and were recognized as having it. However, the way in which Roman law had developed over the previous two or three centuries meant that it was almost inevitable that such force should have been given to at least some juristic opinion. At the core of this was that a major task of the jurists had been to identify and formulate custom. Whilst it might be said that here the binding force of the jurists’ statements lay not in their articulation of the custom but in the very fact that it was the custom of the Roman people, this would have been unsatisfactory in so far as it would have laid the way open for anyone - however unlearned - to deny that the custom was as it had been stated. For the purpose of identifying legal rules, which is the concern of any study of the sources oflaw, the unanimous view ofthejurists was to be treated as conclusive.

On the other hand, if there was disagreement among the jurists the judge was free to decide as he pleased, and since there was room for a good deal of disagreement it would seem to follow that there was a very considerable area in which there was no law. We have no reason to doubt Gaius’s statement, nor the existence of Hadrian’s rescript on which he bases it, but it is nonetheless impossible to believe that the jurists of the second and third centuries would have accepted any conclusion of this sort without some qualification. Very much the reverse: their activity from the late Republic onwards implicitly assumed that it was possible, by the exercise of reason, to identify accurately what the law was in any situation.⁴⁰ Gaius’s statement needs to be understood in a more nuanced way. It was not that there was no law when there was juristic disagree­ment, but that the law was (as yet) indeterminate. There was no clear law that the judge had to follow, but he should take advice and use his own reason to discover what was the ‘true’ rule and to apply it.

It is this seeking after legal ‘truth’ (and the assumption that it exists) that characterizes much of the work of the jurists. Sometimes this involved the identification of the essence of some legal concept. The first-century jurist Labeo, for example, identified the idea of contract with exchange, the Greek synallagma; a century later Pedius identified it with agreement, an analysis that was adopted by Gaius in distinguishing between the claim for the repayment of a loan and the claim for the recovery of money paid by mistake.⁴¹ Sale came to be recognized as an agreement to exchange a thing for money, thereby excluding agreements to exchange things.⁴² Paul defined possession as having a mental and a physical aspect - animus and corpus - thereby framing a way to address the question of whether one still possessed one’s home when away at the market.⁴³ But not all jurists were so happy with definitions. In the second century Javolenus is recorded to have said that ‘All definitions in the civil law are dangerous, for there is hardly any that cannot be subverted.’⁴⁴ More commonly we see the sharpening up of the scope of a rule or legal institution by applying it to variant sets of fact. Thus it was said that ownership could be trans­ferred by traditio, whose core meaning was delivery, without a physical handing over - for example, by pointing to a statue or other large object, or by climbing a tower and indicating the boundaries of land to be conveyed.⁴⁵ In the same vein, Ulpian explored the meaning of corrumpere (spoil), under the third chapter of the lex Aquilia, by examining a whole series of fact situations.⁴⁶ Equally, a rule might simply have been applied to facts without there necessarily having been any sharpening of its scope.

In doing this the jurists used a variety of techniques. Greek dialectic had brought about the division into genus and species in the late Republic, allowing the systematization achieved by Quintus Mucius Scaevola and later Sabinus, whose three books on civil law (his Iuris Civilis Libri Tres) were regularly commented on by the later classical jurists. Principles (regulae) were identified. Building on this, much argument proceeded by making analogies, together with its corollaries, the drawing of distinctions between different cases and the reductio ad absurdum. Etymology, some­times fanciful, could be used to explore the meaning of words. Problems of the interpretation of legal acts - contracts, conveyances of property, wills, and the like - might be elucidated by reference to the actual or presumed intentions of the makers, or by literally construing the terms in which they were couched. Arguments could be made from equity or fairness; Ulpian in particular may have been fond of these. Alternatively, reasoning might be based on utilitas - perhaps close to a modern idea of public policy.

With the notable exception of the Institutes of Gaius, which exists in a near-complete text probably dating from the fifth century, practically all of our knowledge of the work of the jurists comes from the extracts from their writings that appear in Justinian’s Digest.⁴⁷ From this we can see that they composed a variety of types of works: commentaries on the praetor’s edict (especially after Julian’s consolidation) and Sabinus’s lus Civile; collections of real or hypothetical cases; and monographs on a wide range of subjects, including some like criminal law, military law, and testamentary trusts (fideicommissa) which did not fall within the edict. Within this literature they frequently refer to each others’ works: some­times they approve; sometimes they disagree, occasionally vigorously, as, for example, where Paul refers to an opinion of the great Quintus Mucius Scaevola as most inept;⁴⁸ and very often they simply cite without com­ment. Tellingly, they commonly use the present tense when referring to other jurists, even where the earlier writer might have died centuries previously: the common endeavour in which they were all engaged was one which transcended time and was fundamentally anti-historical, how­ever much they were aware that their law had a long history.

It is, therefore, a serious error to suppose that there was a single, uncontroversial Roman law whose content can be discovered from the juristic texts. Its essentially controversial nature, except for the core on which everyone agreed, is brought out by the existence of two distinct schools of jurists in the first century and a half of the Empire: the Sabinians and Proculians. In the brief historical section at the beginning of the Digest, Pomponius, writing about the middle of the second century, describes these schools and allocates the principal jurists of the previous generations to one or other of them. We do not know whether these were educa­tional establishments, although, since the individual jurists undoubtedly engaged in teaching, whether they did so as members of a particular school or not may be an empty question. Clearly, though, there were points of law on which they disagreed, as schools and not just as individual jurists, and substantial traces of these disagreements can be identified in both Gaius’s Institutes and Justinian’s Digest. Whether there was any consistent philosophical basis to their differences is uncertain, and there need not have been any, but their continuity over a century and a half is ample testimony to the way in which Roman law at this time was able to tolerate and incorporate opposing points of view. The schools died out after the middle of the second century - Gaius, a Sabinian, is the last jurist whose allegiance to a school is recorded - but this did not mark an end to juristic disagreement; it was just that it took place at the level of the individual jurist and not by adherence to a group.

Although it is through their writings that the jurists are primarily known to us, an important part of their work was the giving of advice — responsa. Already in the early Republic the pontiffs had done this, and in the third century BC a pontifex maximus, Tiberius Coruncanius, began to give responsa in public,⁴⁹ a practice which continued on the part of the secular jurists from the latter part of the second century. According to Pomponius, a change occurred under Augustus, who granted to some the power to give responsa under the authority of the emperor — the ius publice respondendi.⁵⁰ What exactly this meant is desperately unclear,^{lang=EN-US style='font-size:9.5pt;line-height:115%; font-family:"Arial",sans-serif'>51} but since Pomponius tells us that its purpose was to give greater authority to the law it is probable that it was a response to the uncertainty caused by (self-styled) jurists giving contradictory opinions to litigants and judges and thereby bringing the law into disrepute. Jurists need not seek the privilege — we only know of two who had it — so it is unlikely that it was a prerequisite to giving a responsum which could be cited to a judge, though we might guess that added weight would attach to the opinion of one of these patented jurists: an attractive parallel can be drawn with the appoint­ment of a Queen’s Counsel in the modern world.⁵² It is not clear whether the institution continued in practice after Tiberius, nor whether it changed its function if it did; but in any event Pomponius’s description of it makes it clear that it was abolished by Hadrian, by which time it might already have become moribund.

According to Pomponius, the ius publice respondendi allowed the favoured jurist to give responsa with the authority of the emperor, and the purpose of the institution was to enhance the authority of the law. But nowhere is it suggested that these responsa would have binding authority in the modern sense. In Gaius’s terms, they did not have the force of lex. This was all the more the case with juristic writings, except where all the jurists agreed. Herein lay the fundamental difficulty of the scientific approach which characterized the jurists’ work: any piece of analysis was provisional and at risk of being countered by another jurist with better, or perhaps just different, reasoning. And, paradoxically, the more sophisticated the jurists, the more likely it was that conflicting results might be reached.

The high point of Roman legal science was reached in the late second and early third centuries, with the three greatest of the jurists: Papinian, Paul, and Ulpian. Extracts from the works of these make up a large proportion of Justinian's Digest, testifying to their reputation in the Byzantine world. While they had different approaches to the law - Papinian was perhaps more prone to draw fine distinctions, Paul to seek the essence of legal concepts, Ulpian to favour the pursuit of equity - all three of them were analytically flexible and imaginative in adapting the law to different circumstances. At the same time, responsa to specific questions became more concrete as those who needed to know what the law was in some particular case took advantage of the system of imperial rescripts⁵³ - what one scholar has referred to as a free legal advice service.⁵⁴ Both Papinian and Ulpian were probably secretaries a libellis with respon­sibility for the drafting of these rescripts, so there need be no doubt about their quality at this time. Nonetheless, there was an inevitable tension between authoritative rescripts, which determined the legal point once and for all since they were in theory decisions of the emperor, and the private works of jurists, which were true only to the extent that their reasoning was persuasive. Moreover, as the number of rescripts increased, the more problematic was the scientific approach, since each rescript marked a fixed rule which had to be incorporated into the legal system, however difficult was its fit.

The scientific period of Roman law - what is generally known as the classical period - came to an end in the decade or so after the murder of Ulpian in AD 223. The writing of reflective legal works died out. In part, this was no doubt because political unrest at this time stood in the way of devoting time to it, and the rescript system must have raised questions about the value of attempting to discover the law purely by the exercise of reason. This does not, of course, mean that jurists - legal experts - died out; it was simply that the energies of the best of them were focused on the production of rescripts.

Custom

Although Gaius does not include custom in his list of sources of law, elsewhere in the Institutes he does refer to a form of succession to property as not being introduced by the XII Tables or the praetor's edict but as ‘law [ius] received by common consent'.⁵⁵ Julian - perhaps Gaius's teacher - also referred to custom as the basis of law in this context, but his thought is framed in language which was susceptible of a more general application.⁵⁶ In so far as lex gained its binding force from the consent of the people expressed in their representative assemblies,⁵⁷ all the more should long-standing practices create binding rules even though they were not put into writing. In reality, there was probably little difference between Julian’s position and Gaius’s ascription of binding force to the unanimous opinion of jurists, except that Julian’s treatment provided an intellectual justification for his conclusion whereas Gaius’s did not.

3.