The Latin term ex nunc, of a procedural and material nature, denotes the non-retroactive efficacy of a legal act or judicial decision, projecting its effects exclusively into the future. Its application is fundamental in Constitutional and Administrative Law, aiming to ensure legal certainty and the stability of social relations by limiting the temporal scope of decisions that alter the normative status quo.
Concept and Foundation
The expression ex nunc (from the Latin "from now on") characterizes the prospective effect of a judicial decision or administrative act. Unlike the ex tunc effect, which operates with retroactive efficacy (tunc, "then"), the modulation of ex nunc effects preserves the past, preventing the declaration of nullity or the change in jurisprudential understanding from destabilizing facts already consolidated under the aegis of the previous norm or interpretation.
The legal nature of this institute lies in the protection of legitimate trust and objective good faith. In the Brazilian legal system, the institute is not limited to a mere decision technique, but constitutes a mechanism for controlling the temporality of judicial decisions, being essential to prevent an abrupt change in the legal paradigm from generating a normative vacuum or irreparable damage to the recipients of the norm.
Historical Origin and Evolution
The origin of the institute dates back to Roman Law, but its modern systematization is the result of the transition from classical positivism to neo-constitutionalism. The need for temporal modulation arose with the complexity of the contemporary State, where the annulment of unconstitutional acts could generate administrative chaos. In Brazil, the institute gained definitive contours with the enactment of Law No. 9,868/1999 and Law No. 9,882/1999, which institutionalized the modulation of effects in concentrated constitutional review.
Legal Provision and Normative Structure
The application of the ex nunc effect finds explicit support in the national legal system:
- Art. 27 of Law No. 9,868/1999: Establishes that, when declaring the unconstitutionality of a law or normative act, the Supreme Federal Court (STF), for reasons of legal certainty or exceptional social interest, may restrict the effects of that declaration or decide that it only has efficacy from the moment it becomes final and unappealable or from another moment fixed by the Court.
- Art. 927, § 3º, of the Code of Civil Procedure (CPC/2015): Provides that, in the event of a change in dominant jurisprudence or the thesis established in the judgment of repetitive cases, there may be a modulation of the effects of the change in the interest of social welfare and the principle of legal certainty.
Jurisprudence and Contemporary Application
The Supreme Federal Court (STF) has consolidated the understanding that the modulation of effects is a prerogative of the court, requiring a qualified quorum (two-thirds of the members) for its application. Recently, in general repercussion judgments, the Court has used the technique to avoid budgetary or social destabilization.
Within the scope of the Superior Court of Justice (STJ), the application of the ex nunc effect is recurrent in repetitive appeals, especially in tax and consumer law issues, where a change in interpretation regarding the legality of charges could generate an incalculable liability for financial institutions or the tax authorities.
Related Principles and Doctrinal Divergences
The institute dialogues directly with the Principle of Legal Certainty and the Principle of Protection of Trust. The doctrinal divergence centers on the nature of the modulation: part of the doctrine (such as Gilmar Mendes) argues that it is a power inherent to constitutional review, while critical perspectives point out that modulation can constitute "negative" or "positive legislation" by the Judiciary, theoretically violating the separation of powers.
Contemporary Relevance and Impacts
The relevance of the ex nunc effect is absolute in contemporary times. In a scenario of legal uncertainty, predictability is a market and governance value. The technical application of this institute allows the State to adapt to new constitutional interpretations without suffering the collapse resulting from the indiscriminate retroactivity of decisions, balancing the supremacy of the Constitution with the stability necessary for life in society.
Legal and Jurisprudential References
- BRAZIL. Constitution of the Federative Republic of Brazil of 1988.
- BRAZIL. Law No. 9,868, of November 10, 1999. Provides for the process and judgment of the direct action of unconstitutionality and the declaratory action of constitutionality before the Supreme Federal Court.
- BRAZIL. Law No. 13,105, of March 16, 2015. Code of Civil Procedure.
- SUPREME FEDERAL COURT. ADI 4.451/DF. Rapporteur Justice Ayres Britto. Discussion on the modulation of effects in concentrated control.
- SUPERIOR COURT OF JUSTICE. Repetitive Theme 1076. Discussion on the prospective application of theses for setting attorney's fees.
