ACQUIRED RIGHT. — Can. 10 of the CIC, in conformity with what Roman law established, namely, that a law cannot have effect with regard to facts occurring before its promulgation, enunciates the fundamental principle of the non-retroactivity of laws in the following terms: Leges respiciunt futura, non praeterita, nisi nominatim in eis de praeteritis caveatur.
This principle does not resolve the problem of the effect of the new rule upon a relationship which, having arisen under the authority of the old law, continues to exist under the new discipline. In order to safeguard acquired rights, that is, those rights with respect to which, before the new law entered into force, the requirements for acquisition demanded by the old law had been fulfilled, can. 4 provides: «Iura aliis questa... integra manent, nisi huius Codicis canonibus expresse revocantur». Thus, among the many theories proposed for resolving the aforementioned problem, the canon legislator adopted the theory of acquired rights.
Although it has been doubted whether the rule concerning respect for acquired rights, formulated in can. 4, contains a principle distinct from and independent of that of the non-retroactivity of the law set forth in can. 10, it seems certain to us that the respect for acquired rights established in can. 4 must be regarded as an application of the general principle of the non-retroactivity of the law. It has been pointed out that the sole difference between can. 4 and can. 10 consists in the fact that, whereas in the latter the principle of the non-retroactivity of the law is expressed in an objective formula, in the former the same principle has a subjective formulation, in the sense that the effect of the new law is established with respect to the subjective legal condition of certain specific persons at the time when it enters into force (G. Michiels, op. cit. in the bibliography, p. 69 ff.).
Here the principle of the non-retroactivity of the law must be considered from the standpoint of subjective right, that is, according to the formulation contained in can. 4. The principle of the integrity of the acquired right, established by this canon, presupposes that their rights are retained, even though the CIC has generally abolished them for the future, by those who derived them not immediately from the former laws generally regulating the capacity, status, and relationships of persons and ecclesiastical institutions, but who had individually acquired and preserved them by virtue of an act or fact occurring under the authority of that law.
But these must be genuine acquired rights, that is, rights which had already entered into the patrimony of the person under the authority of the old law, even though the occasion for asserting and exercising them arises under the new law. It is not always possible or easy to distinguish genuine rights from mere expectations, which are nothing other than hopes of rights. But this difficulty concerns the practical application of the theory of acquired rights, since, from the theoretical standpoint, the distinction between acquired right and expectation is not only, as it has seemed to some (cf. R. Naz, Droits acquis, in DDC, XXIV, col. 1514), a didactic expedient useful solely for determining the notion of an acquired right; nor is it so artificial and so unfounded as it has appeared to those who have asserted that it is impossible to provide satisfactory definitions either of acquired right or of expectation, and to those who have maintained that neither category possesses a single characteristic peculiar to it and constituting the difference.
When speaking of acquired rights, it must be borne in mind that what remains acquired is the right in its conceptual and practical unity, and not, instead, its content of powers and faculties; for while the former, once acquired, can no longer be lost, the latter, as well as the manner in which the right itself is exercised, may be modified by the new law. Thus, for example, once the status of spouse has been acquired, a subsequent law can no longer remove it, but it may modify the various rights comprised in it (A. Trabucchi, Istituzioni di diritto civile, Padova 1948, p. 20 f.).
Although the principle that facts and their effects are governed by the law in force at the time when they are performed does not coincide with the principle that the law respects acquired rights, that principle nevertheless entails, at least in many cases, respect for these rights. If a legal fact performed under the authority of a law has caused a person to acquire a subjective right and hence the power to assert it and to assert its effects, then, since the subsequent law does not regulate that fact or its past or future effects, it follows that the subjective right will not be infringed and that the person may assert the right and its effects even after the new law has entered into force. Thus, for example, a law altering the requirements for ordination or for the acquisition of an office would respect the acquired right of the ordained person to exercise Orders and of the person appointed to perform the acts of his office; a law abolishing acquisitive prescription would respect the right of one who had already acquired it previously by completing the prescription; a law modifying the rules of election would respect the right of one who had been elected and had accepted the election (Falco, op. cit. in the bibliography, p. 98).
If the legal fact necessary for the acquisition of a right depends upon the completion, within a specified period, of a series of acts independent of one another, and some of these acts have been performed at the time when the law changed, the acts already performed retain the value they had under the authority of the law in force when they were performed, whereas the acts that remain to be performed are subject to the provisions of the new law. On the other hand, if the legal fact necessary for acquiring a right depends upon the performance of acts which stand to one another in a relation of cause and effect, and some of these acts have been performed when the law was changed, the interested party has an acquired right to perform the subsequent acts according to the old law, except as regards the form of the acts, which is governed by the new law.
It goes without saying that, where the legal fact from which an acquired right derives depends upon a title of a contractual nature, the effects of the contract ordinarily remain governed by the conditions established in it, even if some change occurs in the legislation relating to II.
Since an acquired right is distinct from its consequences, the latter are governed by the law in force at the time when they arise. Thus, for example, in conformity with a response of 23 June 1918 by the commission interpreting the CIC, judicial proceedings arising from betrothals concluded before the CIC entered into force could no longer be instituted after its promulgation, since the CIC had eliminated that action.
As regards the form of acts, the law in force at the time when the acts were performed applies, by virtue of the principle tempus regit actum; the status and capacity of persons must be determined according to the law in force at the time when the capacity is exercised.
With regard to rescripts, reference should be made to the provision of can. 46, according to which rescripta etiam motu proprio concessa... contra ius alteri iam quaesitum, non sustinentur, nisi expressa derogatoria clausula rescripto apponatur. With regard to vows and promissory oaths, it should be borne in mind that dispensation from a vow or oath which infringes another’s acquired right is reserved to the Holy See (cann. 1313, 1320).
Whereas, with regard to rights acquired by virtue of concordats, the principle of the integrity of acquired rights applies without any exceptions whatsoever, with regard to rights acquired by virtue of other titles, including privileges and indults of the Holy See, it does not have absolute force (cf. certain examples cited by M. Falco, op. cit. in the bibliography, p. 69 f.).
meersch - I. Creusen, Epitome iuris canonici, I. Malines-Roma 1940, p. 94 sgg.; R. Naz, Droits acquis, in DDC, IV (1940) coll. 1514-20. Pio Fedele