USI. — It is the traditional opinion (though not without opposition) that usages (u.), understood in the generic sense as equivalent to customs, are sources of objective law. In normative systems of remote periods, and also in certain contemporary systems of traditionalist formation, they have had and retain great importance, although they cannot be considered (as is commonly supposed) the first source in time; indeed, if an essential constituent element of them is vetustas, one would have to suppose that before custom there existed a society without law: an evident contradiction, since law is immanent in every social order. One may admit only that custom can be (not that it necessarily is) the first source containing general and abstract rules. Another constituent element of custom or usage is, according to the common doctrine—though this too is disputed—the opinio iuris necessitatis attributable to the collectivity or social aggregate. There is thus a formation that may be called decentralized or popular, in contrast with the centralized or authoritative formation of legislative sources.
The importance of customs has declined in modern times for various reasons, which may be summarized in two: first, the growing intervention of the State, especially through its legislative organs, in the regulation of intersubjective relations, with a limitation of the autonomy of private persons; secondly, the weakening of a factual premise in the formation of usages, namely, the uniformity over time of the relations regulated—relations which, in modern business practice, may instead undergo rapid modifications or developments. Nor is it always correct that customs respond better than laws to an equitable balancing of the various conflicting interests, since at times they may instead result from the predominance of one category over others, no longer corresponding to changed social conditions and therefore capable of correction precisely through legislative rules, or even through collective agreements or contracts, particularly in economic or labor matters. All such rules, owing also to their written formulation, possess, in comparison with customary rules, a greater degree of precision and certainty and, within certain limits, greater promptness of expression. In international law too, custom, while retaining considerable importance, sees its sphere of applicability limited by the multiplication of treaties and conventions.
Decline does not mean elimination and, in fact, to limit ourselves to Italian law, even the new codes of private law contain provisions referring to usages (the term now preferred by the legislator) or to “normative usages” (legal, juridical), as a large part of the doctrine calls them, in order to distinguish them from the so-called “contractual” usages (business, interpretative, etc.), constituted conventionally, and from “technical” (or factual) usages, followed for reasons of social convenience or practical utility, sometimes possessing significance also in public law (“usages observed as public law,” art. 11 of the Civil Code).
According to the prevailing opinion, custom has validity, if and insofar as it is admitted by statute law, at least in modern legal systems. This does not warrant the a priori and total denial of the admissibility of “innovative or introductory” customs (their admission may be considered undisputed in the case of “interpretative or executive” customs), at least in matters not regulated by positive laws. “Abrogative” customs (or “desuetude”) and customs “modifying” laws, on the other hand, seem unquestionably excluded by art. 15 of the preliminary provisions (“Laws are repealed only by subsequent laws ...”); but it cannot be excluded that this general principle may be derogated from by some particular provision which, explicitly or implicitly, admits repeal or modification in specific cases.
It should be held that the principles indicated remain valid after the entry into force of the new Constitution, although it contains no reference to customs and earlier customs have ceased to have any reason for existence, such as those based on the premise of the termination of the monarchical regime. On the other hand, those based on the premise of the restored parliamentary regime may revive, although it is sometimes difficult to say whether they are true customs or merely constitutional practice or propriety: the former is based on consistent precedents, while the latter rests on ethical and political considerations, which, as such, might constitute an initial step toward the formation of customs but are not in themselves binding.
The problem of inserting usages into the hierarchical system of sources was expressly resolved by the Italian legislator in the sense that they rank after laws, regulations, and also the so-called “corporate rules” (terminology proper to the repealed corporatist system, and now to be understood as “collective labor agreements” or even “economic agreements” among categories of producers, insofar as these remain admissible; cf. preliminary provisions, art. 1 ff.). Different provisions in particular matters remain unaffected; thus, in the matter of maritime, inland-waterway, and air navigation (as previously in commercial matters), usages, while remaining subordinate to the statutory law governing the matter itself, nevertheless prevail over ordinary civil law (art. 1, Code of Navigation). Local and special usages prevail over general ones, by virtue of the principle that, among sources of the same type, the source containing a special rule prevails over one containing a general rule. Collections of usages are compiled by the Chambers of Commerce, Industry and Agriculture.
BBL.: the Italian and foreign bibliography, both ancient and recent, is very extensive; cf., also for other references. N. Bobbio, La consuetudine come fatto normativo, Padova 1942; C. Carbone, La consuetudine nel diritto costituzionale, ivi 1948; G. Moricheccucci, Gli u. normativi come fattispecie, Genova 1948; F. Pergolesi, Sistema delle fonti normative, 3ª ed., Bologna 1949. Ferruccio Pergolesi