Lex or Senatusconsultum which enumerates powers conferred on the Emperor Vespasian at his accession Ref. 134. The rights of the Princeps enumerated in this document are of a very heterogeneous kind—they include the powers of making treaties, extending the pomerium of the city, commending candidates for office, and issuing edicts as interpretations of law, human and divine; and, important as they are, they have no direct connexion with either the Proconsulare Imperium or the Tribunicia Potestas. Some of the most imposing powers of the Princeps were dependent on neither of these two sources, but were contained only in this general Lex; and as fresh prerogatives were added to the Principate, the Lex would grow in bulk and importance. Some development of this kind may account for the fact that Gaius and Ulpian both speak of the Princeps receiving his Imperium through a Lex Ref. 135. Such an expression could not have been used of the early Principes; for the Proconsulare Imperium was received through a decree of the Senate; but it is possible that in the course of time the general Lex, as enumerating the majority of the prerogatives of the Princeps, came to overshadow the other sources of his authority.
Since the authority of the Princeps was built up in this gradual and unsystematic way, it is quite impossible for the modern inquirer to determine with precision the sources of the exercise of his different powers. But a rough estimate may be made of five distinct kinds of prerogative and of the activities flowing from each. (1) With the Imperium were connected the control of the army and the provinces, the right of declaring war and of making treaties, the power of conferring Roman citizenship or Latin rights, civil and criminal jurisdiction, and the general power of legal interpretation. (2) The Tribunician Power, besides making the Princeps sacrosanct, gave him the right, exercised during the earlier period of the Principate but afterwards neglected, of initiating measures in the Assembly of the Plebs, and also the right of transacting business with the Senate, although this second right was extended by special grants. The power of veto, inherent in the Tribunicia Potestas, gave the Princeps a control over all the other magistrates of the State, enabled him to exercise over the jurisdiction of the Senate a power akin to that of pardon, and probably formed the basis of much of his appellate jurisdiction. (3) Two of the Principes, Claudius and Vespasian, were invested with the temporary office of censor, and Domitian declared himself censor for life. His example was not followed by succeeding rulers; but the most important of the functions of the censors—the revision of the lists of Senators and Knights—continued to be a part of the admitted prerogatives of the Princeps. Akin to this right was that of creating Patricians, which had been conferred by law on Caesar and Augustus, had been exercised by Claudius and Vespasian as censors, and finally became a right inherent in the Principate itself. (4) The Princeps, besides being a member of all the great religious colleges, was, as Pontifex Maximus, the official head of the state-religion, and was invested by law with the power of executing ordinances which were to the interest of the religious life of the community Ref. 136. (5) Supplementary powers, which cannot be described by a common name or connected with any definite office, were granted to the Princeps. Some of these were means by which his control over the magistrates and the Senate was increased. Such were the rights of securing the election of certain candidates for office by means of a recommendation (Commendatio), and of exercising powers in relation to the Senate superior to those possessed by the other magistrates.
An authority thus endowed could not fail to exercise a strong directing influence on the sources of law and the methods of procedure. The influence asserted itself from the first; yet for at least two centuries there was always a formal, and sometimes a real recognition of the theory on which the Principate was based—the theory of a dual control exercised by the Princeps on the one hand, by the usual organs of the Republic on the other. The chief organ by which the Republic was represented was now no longer the People, but the Senate; and the dual sovereignty—or ‘Dyarchy,’ as it has been called—can be illustrated chiefly by the division of authority between the Princeps and the Senate.
As regards the sources of law, even the utterances of the People were for some time elicited. Leges and Plebiscita—specimens of which are to be found in the Leges Juliae of Augustus, the Lex Aelia Sentia belonging to the reign of the same monarch, the Lex Junia Norbana of the reign of Tiberius, the Leges Claudiae of the Emperor Claudius — continued to be passed during the early Principate. The last trace of legislation belongs to the reign of Nerva (96-98 a. d.) Ref. 137.
Even before legislative power had been surrendered by the Comitia, it had begun to pass to the Senate; and down to the third century a.d., such general ordinances as tended to alter the fundamental legal relations of Roman citizens to one another were generally expressed in the form of Senatusconsulta. The Senatusconsultum was a true source of the Jus Civile. Yet it did not attain the formal structure, or always adopt the imperative utterance, of a law. Its utterances are often couched in an advisory form Ref. 138, as though the Senate of this period, like that of the Republic, were merely giving counsel to a magistrate. Gaius attributes to these decrees ‘the binding force of law’; and it does not seem that the early doubts as to whether the Senate could pass ordinances immediately binding on the community Ref. 139 survived the beginning of the Principate.
The Praetor’s edict still continued to be issued; nor are we told that the edictal power was in any way infringed during the early Principate. But there are two considerations which would lead us to conclude that it was seriously weakened. The first is based on the fact that edictal power in the highest degree was conferred by law on the Princeps himself Ref. 140; and the existence of two interpreters of the civil law possessing equal authority is almost inconceivable. The second consideration rests on the probability that the Praetor’s rulings in detail were subject to the veto of the Princeps. A new ruling was often the basis for a new formula and a new edict, and if the first of these was inhibited, its successive developments could not be realized. Progressive legislation was effected elsewhere, in decrees of the Senate and in the imperial constitutions; and the final sign that the creative work of the Praetors was a thing of the past was given when, in the reign of Hadrian (117-138 a.d.), and therefore probably in the lifetime of Gaius, the work which Ofilius had begun Ref. 141 was perfected by the jurist Salvius Julianus. He reduced the edict to a fixed and definite system Ref. 142; and from this time onward the Edictum Perpetuum was, in its essential features, unalterable. Absolute validity was given to the new redaction by a Senatusconsultum introduced by a speech from the Emperor Hadrian, who declared that any new point, not contemplated in the edict, should be decided by analogy with it Ref. 143. It is probable that such new points were still mentioned in successive edicts; for it is certain that the edict still continued to be issued annually. The work of Julian could, therefore, never have been meant to be unalterable in a literal sense. Such invariability would indeed have been impossible; for, though changes in law were now beginning to be made chiefly by ordinances of the emperor, yet these very changes would necessitate corresponding changes in the details of the edict. The fixity of Julian’s edict was to be found both in its structure and in its leading principles; in the order in which the rules of law were marshalled and in the general significance of these rules. It has been supposed that Julian’s work was not confined to the edict of the Praetor Urbanus, but that he dealt also with the edicts of the Praetor Peregrinus and of the Curule Aediles Ref. 144. He may have treated these edicts separately; but the three may have been combined in a single comprehensive work which was spoken of as ‘The Edict Ref. 145.’
By the side of these sources of law which survived from the Republic stood the new authority, the Princeps. He was not regarded as, in the strict sense, a legislative authority; but he or his advisers exercised a profound influence on the growth and structure of law in virtue of his power of issuing Edicts, Decrees, Rescripts, and Mandates. The Edictum of the Princeps was, like that of the Praetor in the Republic, technically an interpretation of law, but, like the Praetor, the Princeps could supplement and alter under the guise of interpretation: and his creative power, as exercised by his edictal authority, was very great. An edict of an emperor did not necessarily bind his successors; but, if it had been accepted as valid by a series of emperors, it was considered to be a part of the law, and its subsequent abandonment had apparently to be specified by some definite act of repudiation Ref. 146. The Decretum was a
