RETROACTIVITY OF THE LAW. — The CIC adopted the principle of the non-retroactivity of the law, establishing that leges respiciunt futura, non praeterita, nisi nominatim in eis de praeteritis caveatur (can. 10). This principle, common to every legal system, is one of those principles of intertemporal law that seeks to provide a criterion for resolving cases in which a new legal rule, regulating a matter already subject to another form of regulation, encounters relationships that began under the old rule and reach completion under the new one, or that, having been established under the old rule, produce their effects during the reign of the new one.
Among modern canonists, whose attention has been drawn by the aforementioned norms of the CIC and by those of can. 4, which expressly mentions the iura aliis quaesita, establishing that ... integra munent, nisi huius Codicis canonibus expresse revocentur, some have attributed to the principle the value of an absolute limit on the efficacy of the rule. One gives prominence to the purpose of the law, which is one of the many aids to which the interpreter must have recourse, but presents the serious shortcoming of failing to specify how the interpreter should proceed where the purpose is not clear; others, finally, have adhered to other and different theories. The truth is that every doctrine has a certain foundation, and the key to the entire problem can be found only by taking from each theory its element of truth. Indeed, first of all it is necessary to distinguish, within the so-called principle of the non-retroactivity of the law, two fundamental aspects that must be kept entirely separate: the pre-legislative or de iure condendo aspect and the legislative or de iure condito aspect. With regard to the former, it must be said that this is an ethical limit—one of the many imposed upon the conditor legum—and it is a problem of value that no legislator, and especially not the canonical legislator, may disregard; indeed, the authority governing every society finds an ethical limit to its powers of government in the good of its subjects, not only uti universi but also uti singuli, in the sense that legislative enactments should not, except where the common good itself requires it, injure the individual or the sphere of good that the latter has secured for himself through conduct conforming to the precepts established by that same legislator. Indeed, from this pre-legislative perspective, Bartolo da Sassoferrato (In primam digesti veteris partem Commentaria, Venice 1585, tit. de iustitia et iure, l. omnes populi), in resolving the highly interesting case of a city that, after granting tax exemption to anyone immigrating there, wished to revoke the provision even to the detriment of those who, attracted by the exemption, had settled there, spoke of a “quasi-contract” between the subject to the law and those who had enacted the law, expounding a concept entirely consonant with the foundational concept of the principle of the non-retroactivity of the law. Under the other aspect, however, the principle, insofar as it is a directive for the person who must apply the law, consists entirely in establishing which law regulates a concrete legal relationship extending through time, and is a question of fact or, more precisely, of positive law.
Even as a matter of positive law, however, the problem under examination must not be confused either with that of retroactivity as ex tunc efficacy, which is very frequent in legal transactions but not uncommon in law as well, in the sense that a rule enters into force from a moment prior to its drafting, promulgation, or even to the time when it is brought to the knowledge of the subjects. Indeed, in this regard, the very retroactivity of the merely interpretative law established by can. 17 CIC has nothing contrary to the general principle of non-retroactivity, but fits within it without even constituting an exception.
Since the law is above all a rule governing acts, it must precede the act and not follow II. This is the reason for institutions such as the publication of laws and the vacatio, by which the rule takes effect only after the necessary conditions have been fulfilled for the rule to come to the knowledge of its addressees.
A rule that produces its effects from a moment prior to that of its promulgation is retroactive, just as a legal transaction is retroactive when its effects reach back to a moment prior to that of its conclusion; but this retroactivity, known to the legislator and indeed expressly provided for with regard to the more favorable penal law (can. 2226 § 2), has nothing to do with the retroactivity excluded by can. 10. When the judge applies the more favorable rule, which hypothetically may be that in force at the time when the offense was committed rather than that in force at the time when the offender is tried, it cannot be said that he does so on the basis of the principle of non-retroactivity. When, on the other hand, one speaks of a principle of the non-retroactivity of the law, one simply means that the legislator, placing this principle among those of positive law, intended to refer to the pre-legislative principle and transpose it into the legislative system, while reserving for himself—nisi nominatim... de praeteritis caveatur, as he himself said—the fullest formal freedom in enacting rules and delimiting their efficacy with regard to time.
Since every law is enacted because the legislator has considered it necessary to satisfy a requirement of the social order, that order may also justify regulating relationships established before the law entered into force. The judgment as to whether it is expedient to regulate those relationships as well is reserved to the legislator himself; for the interpreter, therefore, the problem is reduced to an interpretation of the legislator’s will and hence of the will expressed in the rule.
Starting from this fundamental premise, it may be that the legislator allows one to understand what the practical application of the rule should be, perhaps establishing that it is to exert its influence even upon relationships originating in the past. In this case the concrete rule may be retroactive even if the legislator does not say so nominatim, provided that retroactivity can be inferred from the content of the new rule, although in many cases the CIC has used the formula non obstante quolibet privilegio, or reprobata quocis contraria consuetudine.
Conversely, the legislator may use a formula leaving no doubt as to the non-application of the rule to relationships already established, as when it established that nullum patronatus ius... constituit in posterum valide potest (can. 1450 § 1), or that ut quis in parochum valide assumatur, debet esse in sacro presbiteratus ordine constitutus (can. 453 § 1). In both of the cases cited, it may be said that no genuine problem of the non-retroactivity of the law exists from a legal standpoint.
The problem is more delicate where the new law does not encounter relations that have already been concluded, but pending relations, either because it concerns a composite fact in which only some of its constituent elements have been verified, or a fact that is perfected only through the passage of a determinate period of time, or because a relation that has already arisen validly continues its execution during the period following the promulgation of the new law. In the first two cases, doctrine has provided a satisfactory solution, holding that, in cases of pending status resulting from the non-completion of the relation, the effectiveness of the new norm is made explicit. More difficult, however, is the solution where the so-called relations
of successive performance are involved; but here, given the centuries-old canonical practice, it must be held that the only criterion that may be called upon for assistance is that of the acquired right, adopting it, however, not in opposition to the objective criterion of the accomplished fact, as some canonists have claimed, but as a complement to and an integration of II.
Can. 4, which establishes respect for the acquired right (v.)—and which constitutes a transitional norm for the internal legal order, just as can. 3 established such respect for the external legal order—has a different value from the norm of can. 10, inasmuch as the latter applies to all legislation, whereas the former limits its effectiveness to the sphere of the CIC. This does not prevent the two provisions from being integrated as follows: «laws concern the future and are not retroactive, that is, they do not infringe rights already acquired before they entered into force».