Res judicata (claim preclusion) constitutes a fundamental institute of Civil Procedural and Constitutional Law, defined as the immutability of a judicial decision on the merits against which no further appeals can be filed. Its primary purpose lies in the stabilization of legal relations and the guarantee of legal certainty, preventing the rediscussion of disputes already resolved by the Judiciary.
Concept and Foundation
Res judicata, technically referred to as res judicata, transcends the mere conclusion of a lawsuit; it represents the preclusive effect that renders a court order indisputable. Legally, it is classified as a quality of the judgment, devoid of the nature of an administrative act, but rather a sovereign manifestation of state jurisdiction. Classical doctrine, led by authors such as Liebman, distinguishes formal res judicata—which closes the process without resolution on the merits—from material res judicata, which makes the content of the decision immutable, preventing new lawsuits regarding the same object and cause of action.
Historical Origin and Evolution
The genesis of the institute dates back to Roman Law, under the maxim res judicata pro veritate accipitur (the thing adjudged is accepted as truth). The Roman system sought, through the authority of the magistrate, to provide certainty to judgments, avoiding perpetual conflict. In the Brazilian legal system, the institute evolved from a purely private view to a constitutional pillar, being elevated to the category of a fundamental guarantee, aiming at social pacification and the protection of the citizen against the arbitrariness of procedural reiteration.
Legal and Constitutional Provision
The Brazilian legal system grants express constitutional protection to res judicata, pursuant to Article 5, item XXXVI, of the 1988 Federal Constitution, which prohibits laws from harming acquired rights, perfect legal acts, and res judicata. In the procedural scope, the 2015 Code of Civil Procedure regulates the institute in articles 502 to 508, defining material res judicata as the authority that makes a decision on the merits, no longer subject to appeal, immutable and indisputable.
Practical Application and Jurisprudence
The application of res judicata is absolute regarding legal certainty, except for the exhaustive hypotheses of rescissory action (art. 966 of the CPC). The Supreme Federal Court (STF) consolidated relevant understanding in Theme 881 (RE 949.297) and Theme 885 (RE 955.227), establishing the thesis that a decision declaring the constitutionality or unconstitutionality of a continuous-tract tax, rendered by the STF, ceases the effects of res judicata to the contrary, harmonizing the principle of legal certainty with tax equality.
Furthermore, in the field of labor procedure, the Superior Labor Court (TST) maintains Precedent (Súmula) No. 268, which reinforces the preclusive effect of res judicata, preventing the rediscussion of claims not requested in a previous action, provided that the request could have been formulated.
Related Principles and Doctrinal Divergences
The institute is intrinsically linked to the principle of legal certainty and the principle of due process of law. A notable doctrinal divergence occurs in relation to "unconstitutional res judicata." While part of the doctrine defends the absolute prevalence of immutability, another current, based on the supremacy of the Constitution, maintains that a sentence based on a law declared unconstitutional, or that frontally violates the constitutional order, should not produce immutable effects, being subject to deconstitution even after the deadline for the rescissory action.
Contemporary Relevance
In contemporary times, res judicata faces the challenge of the "effectiveness crisis." The increase in litigation and the need to adapt decisions to new factual contexts—especially in continuous-tract relations—force the Judiciary to balance the authority of the sentence with social reality. Jurisprudential evolution points to a less rigid interpretation in cases of concentrated control of constitutionality, without this implying the emptying of the institute, which remains the anchor of predictability in the Democratic State of Law.
Legal and Jurisprudential References
- BRAZIL. Constitution of the Federative Republic of Brazil of 1988. Art. 5, XXXVI.
- BRAZIL. Law No. 13.105, of March 16, 2015. Code of Civil Procedure. Arts. 502-508 and 966.
- SUPREME FEDERAL COURT. Extraordinary Appeal 949.297 (Theme 881) and 955.227 (Theme 885). Rapporteur: Justice Edson Fachin, 2023.
- SUPERIOR LABOR COURT. Precedent No. 268: "Res judicata. Preclusive effect".
- LIEBMAN, Enrico Tullio. Eficácia e Autoridade da Sentença e Outros Escritos sobre a Coisa Julgada. Rio de Janeiro: Forense.
