JURISPRUDENCE. — From the Latin *iurisprudentia*, it signifies expertise in law, an expertise that is at once theoretical science and practical wisdom. Such, indeed, is the value of the Latin *prudentia*, corresponding to the Greek *φρόνησις*.
This is how the Romans understood and defined jurisprudence (*g.*): for them, it was both the science and the art of law; in the famous definition of Ulpian: “Iurisprudentia est divinarum atque humanarum rerum notitia, justi atque iusti scientia” (D. I, 1, 10, 2), jurisprudence is pre-eminently the science of justice, conceived as the supreme norm governing all relationships in life—legal, moral, and religious.
At present, in its broadest sense, *g.* denotes the science and practice of law; in this sense, it is also common to group the various branches of legal science under the general heading of *g.*
In its strict and specific sense, however, the term *g.* now refers to only one particular aspect of legal activity and, from the material objective standpoint, indicates the production of judicial organs that apply law to factual relationships—that is, the body of decisions issued by the various courts in the exercise of their function of practical application of the law. From the formal objective standpoint, it is the very concrete interpretation of existing laws consistently rendered by the courts, namely, the body of legal principles resulting from the uniformity of judgments concerning the same type of relationships. Such principles come into being when multiple judgments coincide in their specific legal element (the *ratio decidendi*), that is, in the assessment of the facts in relation to the application of the same statutory provision. They correspond to as many concrete and tested interpretations of the law itself and, in turn, may serve as norms in the resolution of disputes of the same kind.
The Romans defined jurisprudence, thus conceived, as “autoritas rerum perpetuo similiter iudicatarum” (D. I, 3, 38) and recognized its value, even though the principle later embraced by the Glossators was also in force: “Ne exemplis, sed legibus iudicetur” (C. 7, 45, 13). Among the Glossators, it is known as *usus forensis* or *praxis judicialis*. Canonists identified it with *stylus judicialis*, a notion that, however, has always been broader, including the concept of procedure in general, even in its purely formal aspects.
Taken in this sense, jurisprudence encompasses all the various branches of law and is specified as civil, criminal, commercial, ecclesiastical, etc., according to the subject matter of the science and the nature of the judicial organ. Sometimes, by analogy, the uniform manner of decision-making by administrative organs is also called *g.*, though the more proper term for this is administrative practice.
The immediate and specific task of jurisprudence is to interpret laws and apply them to the case at hand; its mediate task is to guide the interpretation and application of those laws toward stability and certainty, thereby providing authoritative guidance for future decisions of the same kind. Through judicial interpretation—which canonists term “interpretation per modum sententiae judicialis” (can. 17 § 3) and which, among the various forms of interpretation, plays a primary role, indeed superior in practice to that of the legislator’s authentic interpretation—jurisprudence, as the judicial interpretation enshrined in the consistent uniformity of judgments, becomes in reality the pre-eminent forge of legal refinement, whereby laws are rendered applicable to concrete cases. Even doctrinal interpretation, which is otherwise utilized here as the principal collaborator, sometimes undergoes a process of reworking that aligns it with the jurisprudential direction.
This activity of jurisprudence is both conservative and innovative. On the one hand, it guides the interpretation of new laws along the tracks of traditional orthodoxy, ensuring their relevance without compromising fundamental legal principles; on the other, as laws age, it subjects them to a slow, assiduous process of revision and renewal that ensures harmony between the norms of objective law and the exigencies of life. These are two distinct activities that, however, converge toward the single goal of keeping laws alive and operative without detriment to the legal system of which they are part.
In this way, jurisprudence extends and prolongs its task beyond the immediate interpretation of legislative texts to become not only the safeguard of legal orthodoxy but also the most important factor in the development and systematization of law, a sure preparation and guide for the reforming work of future legislators. It also possesses the coordinating activity of various norms and interpretations, a most important function that lends uniformity and certainty to laws and security to the citizens who must observe them.
It is now easy to understand what the historical role of jurisprudence has been in other eras and why it has earned such great merit (it suffices here to recall Roman law).
It is true that in more recent periods, for example in the 18th century, jurisprudence underwent crises of delay in its activity and showed signs of fatigue and disorientation in the performance of its functions. It has been reproached, and sometimes still is, for unreasonable conservatism, insensitivity to real moral and social needs, formalistic spirit, excessive attachment to the letter of the law, and above all for excessive susceptibility to fluctuations and contradictions. But, apart from the unsubstantiated nature and exaggeration of some of these criticisms—often advanced by those lacking specific competence, more often than not literary figures, historians, and philosophers—it must be noted that many of these defects are attributable less to jurisprudence itself than to the historical crisis of law, the diversity and plurality of legal systems, and especially to deficient legislation.
Nevertheless, no matter how great the authority of jurisprudence may be, it is never such as to confer normative efficacy or bind the decisions of the courts.
To deduce the obligatory force of jurisprudence by considering it from the standpoint of custom is to shift the issue, since the question here is not whether a custom obliges but whether jurisprudence obliges in itself. Moreover, although the uniform and constant adoption of a jurisprudential approach may in fact give rise to a usage, this cannot constitute a true custom, since the requisite conviction on the part of the community that the approach itself is obligatory is lacking. That the *opinio iuris* of judges can substitute, in this case, for the missing *opinio iuris* of the community, as some authors claim, is an unfounded assertion.
Nor is it valid to invoke analogies with institutions proper to foreign legal systems, for example, with the *arrêtés de règlement* of the old French parliaments, which once had the force of law within the jurisdictional scope of the parliament that issued them, or with the current *bindings* or *authoritative precedents* (decisions constituting authoritative precedents) of higher courts in Anglo-Saxon countries governed by the common law, which make law for lower courts. Although there is undeniable similarity in these institutions, it would be erroneous to claim that they reproduce exactly the *autoritas rerum perpetuo similiter iudicatarum*.
Different solutions to the problem are offered by canonists, especially those of the medieval period. On the basis of a decretal by Innocent III, which introduced into ecclesiastical law the efficacy of Justinian’s *Constitutio Imperalis* (C. I, 1, 12) and enunciated the value of jurisprudential precedent (*giurisprudenza*), ancient canonists first attributed universal legislative efficacy to the decisions of the Supreme Pontiff: a doctrine later abandoned with the general acceptance of the principle *sanctio* now found in can. 17 § 3. They further attributed legal force to jurisprudential precedent, though not as law *per se*, but as *usus fori* and as custom. To establish such precedent, they deemed sufficient even two conforming judgments rendered within a decade, and sometimes even a single judgment given in adversarial proceedings, provided that the *consensus populi* was evident—upon which, more than upon the repeated conformity of acts, the juridical efficacy of custom was then held to depend. Jurisprudential precedent itself, therefore, does not appear to have been regarded as a source of law. The doctrine of secular glossators was not greatly dissimilar at the time. Even today, despite the uncertain fluctuations among many of the best canonists, the prevailing doctrine remains rooted in the same positions. It is affirmed that jurisprudential precedent in itself does not make law, as can readily be inferred from can. 17 § 3; law is made, however—especially when the precedent arises from the decisions of the Apostolic tribunals—when custom concurs. For this reason, it is taught that precedent acquires such efficacy only when it is *firma*, that is, when, after an adequate number of conforming decisions, the necessary time has elapsed for custom to prescribe II. Yet this doctrine is not without doubts and difficulties, chief among them being the objection that in such cases the *communitas legis recipiendae capax*—a constitutive element of every custom (can. 26)—is lacking, by which the repetition of acts and the *animus obligandi* are realized. To claim that the *communitas* is here supplied by the legislator’s consent is to ignore the precise wording of can. 26. Nor should the approach of ancient canonists be misleading, for at that time custom derived its efficacy from principles later partly abandoned. Moreover, the fact remains that even at the Sacred Roman Rota a jurisprudential maxim is never, in practice, considered so absolute as to be immune from correction by future decisions.
While denying to jurisprudential precedent the efficacy of a productive source of law, it is nonetheless recognized as possessing the highest moral authority; it is undeniable that a jurisprudential trend, when consistently adopted by tribunals and tested by long and uniform observance, imposes itself as a norm of conduct that is morally obligatory. This is a moral authority, far nobler and no less effective than juridical authority, inasmuch as it binds not by reason of power (*ratione imperii*), but by the power of reason (*imperio rationis*).
The value of jurisprudential precedent varies according to the rank and authority of the body from which it emanates. In the Italian legal system, the highest authority is accorded to the precedents of the Court of Cassation, while in ecclesiastical law it is accorded to those of the Sacred Roman Rota and the Apostolic Signatura. The value of precedent also varies according to the degree of uniformity, in spatial terms, and the degree of constancy, in temporal terms, with which the jurisprudential maxim has been adopted and followed by the various courts. Hence, there is a distinction between precedent that is both conforming and constant, and that which is merely conforming or merely prevalent.