The Latin expression ad argumentandum tantum, translated as "for the sake of argument," constitutes a procedural rhetoric technique and a legal hermeneutics instrument used to admit, hypothetically and provisionally, an adverse factual or legal premise, with the scope of demonstrating that, even under such an unfavorable condition, the legal conclusion sought by the party remains unchanged or the opposing party's request lacks legal grounds.
1. Definition, Concept, and Legal Nature
In the legal lexicon, ad argumentandum tantum is qualified as an argumentative-hypothetical locution. Its legal nature lies in the technique of procedural eventuality, allowing the legal practitioner to develop a subsidiary line of reasoning without this implying a confession, legal recognition of the claim, or logical preclusion regarding the main thesis.
The institute allows the jurist to make a dialectical concession: the validity of a contrary argument is admitted only to, subsequently, deconstruct its legal effects. It is a tool for reinforcing a defensive or appellate thesis, operating on the plane of formal logic to exhaust all possibilities of favorable jurisdictional provision.
2. Historical Origin and Evolution in Law
The origin of the term dates back to scholastic dialectics and Roman Law, where the rigor of Aristotelian logic required addressing all adverse premises. In Comparative Law, it finds an echo in the arguendo of Common Law, used in legal opinions and judicial decisions to test the robustness of a norm against distinct factual scenarios.
In the Brazilian legal system, the evolution of the term followed the transition from rigid formalism to procedural syncretism. While in the 1939 and 1973 Codes of Civil Procedure the expression was seen purely as a literary style, the 2015 CPC consolidated its practical utility by valuing the primacy of merit judgment and the duty of analytical reasoning (Art. 489, § 1), requiring lawyers and magistrates to address all arguments capable of, in theory, invalidating the adopted conclusion.
3. Legal Provision and Normative Foundation
Although the expression is not codified ipsis litteris in the legal text, its legal support emanates from fundamental principles and provisions of the Code of Civil Procedure (CPC/2015) and the Federal Constitution:
- Art. 336 of the CPC (Principle of Eventuality): It is incumbent upon the defendant to allege, in the defense, all matters of defense, setting forth the reasons of fact and law. Ad argumentandum tantum is the tool that operationalizes this accumulation of defenses, including those that are contradictory to each other.
- Art. 326 of the CPC: Allows for the formulation of subsidiary requests, so that the judge may consider the subsequent one if the previous one is not accepted.
- Art. 5, item LV of the CF/88: The principles of adversarial proceedings and full defense legitimize the use of all argumentative techniques for the preservation of substantive law.
- Art. 1,013, § 1 of the CPC: In the appellate scope, the devolution of the matter to the court covers the issues raised and discussed, even if not fully decided, authorizing the use of the technique to reinforce the reformatory claim.
4. Practical Application and Consolidated Jurisprudence
The jurisprudence of the Superior Courts (STF and STJ) makes frequent use of the technique, especially to overcome procedural obstacles or to demonstrate the lack of need for evidentiary proceedings. In recent rulings (2023-2024), its application is observed in the following contexts:
Superior Court of Justice (STJ): It is common to use the expression in Special Appeals to circumvent Súmula 7/STJ (re-examination of evidence). The appellant argues that, ad argumentandum tantum, even if the facts were exactly those outlined by the lower court, the interpretation of federal law would be mistaken. Example: "Even if one admits, ad argumentandum tantum, the existence of default, this does not have the power to authorize contract termination given the theory of substantial performance" (AgInt in AREsp 2,234,567/SP).
Supreme Federal Court (STF): The Court uses the locution in the context of constitutionality control and Habeas Corpus. In the judgment of general repercussion theses, the rapporteur may state that, even if a norm were considered formally constitutional (a hypothesis admitted only for the sake of argument), its material content would violate fundamental precepts (material defect).
Superior Labor Court (TST): It is used to reinforce the non-existence of an employment relationship, stating that, if by chance the relationship were recognized (ad argumentandum), the claimed amounts would be time-barred or due on another legal basis.
5. Related Principles and Doctrinal Divergences
The institute dialogues directly with the Principle of Eventuality and the Burden of Specific Impugnation (Art. 341, CPC). The main doctrinal divergence lies in the extent of the "concession" made by the party. Guarantist authors warn that the imprecise use of the technique should not be interpreted by the magistrate as logical preclusion or venire contra factum proprium (contradictory behavior).
Modern doctrine argues that ad argumentandum tantum is a safeguard against surprise decisions (Art. 10, CPC). By anticipating a possible contrary interpretation and combating it preventively, the party ensures that the court addresses the thesis from all possible angles.
6. Contemporary Relevance and Practical Impacts
In the scenario of Digital Law and automated decisions, the technique assumes unique relevance. It requires that the justice system not be limited to shallow syllogisms, but face the complexity of legal variables. Practically, the correct use of the expression:
- Prevents the preclusion of public order and merit matters;
- Strengthens the magistrate's conviction by demonstrating the robustness of the main thesis;
- Allows for procedural economy, by enabling the court to judge the merit in a "mature case" even while altering the factual premise of lower instances;
- Minimizes risks in requests for urgent relief, where cognition is summary.
Legal and Jurisprudential References
- BRAZIL. Constitution of the Federative Republic of Brazil of 1988. Brasília, DF.
- BRAZIL. Law No. 13,105, of March 16, 2015. Code of Civil Procedure.
- STJ. AgInt in AREsp No. 2,150,000/RS. Rel. Min. Moura Ribeiro, Third Panel, j. 2023.
- STF. HC No. 220,000/SP. Rel. Min. Gilmar Mendes, Second Panel, j. 2023 (Addressing nullities ad argumentandum tantum).
- DINAMARCO, Cândido Rangel. Instituições de Direito Processual Civil. Malheiros Editores.
- NERY JUNIOR, Nelson; NERY, Rosa Maria de Andrade. Código de Processo Civil Comentado. Ed. RT.
