The fumus boni iuris, or smoke of good law, constitutes a fundamental precautionary requirement in Brazilian Procedural Law, operating as a judgment of probability regarding the existence of the alleged substantive right. Its primary purpose is to enable the granting of urgent or evidence-based relief, ensuring the effectiveness of the final judicial decision in the face of the risk of harm or procedural inefficiency.
Concept and Foundation
The fumus boni iuris is not to be confused with legal certainty, but rather with the plausibility of the claim. It is a logical verisimilitude that, combined with periculum in mora, authorizes the magistrate to anticipate procedural effects. In terms of legal dogmatics, the institute has the nature of an admissibility condition for the granting of provisional measures, being a summary cognition judgment that does not exhaust the merits of the case.
Historical Origin and Evolution
The genesis of the institute dates back to Roman Law, consolidating itself in the Italian procedural tradition, especially in the works of Piero Calamandrei and Giuseppe Chiovenda. Classical procedural doctrine established that for the State-Judge to intervene preventively, full proof is not required, but rather a demonstration that the invoked right is probable. In the Brazilian legal system, the concept was absorbed and improved by the 1973 Code of Civil Procedure and, subsequently, structured with greater technical rigor by the 2015 Code of Civil Procedure.
Legal Provision
The current national codification establishes the requirements for granting urgent relief in Article 300 of the 2015 CPC, which replaced the classic Latin expression with "probability of the right." In the scope of Criminal Procedure, the institute is implicit in the precautionary measures provided for in Articles 312 and following of the Code of Criminal Procedure, being a prerequisite for preventive detention and other precautionary measures other than imprisonment, requiring proof of the existence of the crime and sufficient evidence of authorship.
Practical Application and Jurisprudence
The jurisprudence of the Superior Courts has consolidated the understanding that the analysis of fumus boni iuris must be carried out with caution to avoid prejudgment. The Superior Court of Justice (STJ), in repeated rulings, defines that the "probability of the right" requires the plaintiff to demonstrate that, in a perfunctory analysis, the claim presents solid foundations. In the context of a writ of mandamus (mandado de segurança), Supreme Court (STF) Súmula 625 and related jurisprudence reinforce that pre-constituted evidence is the vehicle for demonstrating the smoke of good law.
Doctrinal Divergences and Related Principles
There is a doctrinal current that discusses the replacement of Latin terminology with vernacular terms, arguing that the "probability of the right" brought by the 2015 CPC carries more technical semantic weight than "smoke." However, the majority doctrine, including names such as Fredie Didier Jr., argues that the essence of the institute remains unchanged, being a value judgment on the probability of victory in the final demand. The principle of procedural effectiveness is the vector that supports the need for this institute, allowing the process not to be futile.
Contemporary Relevance
Currently, the institute is a pillar for the stabilization of relief and for procedural speed. In times of judicialization of health and high-complexity demands, the assessment of fumus boni iuris allows the Judiciary to intervene in a timely manner to avoid irreparable damage, such as in the case of providing medication or suspending harmful administrative acts. The technical analysis of this requirement is what differentiates a reasoned judicial decision from a discretionary act, providing legal certainty to the litigant.
Legal and Jurisprudential References
- Brazil. Law No. 13,105, of March 16, 2015. Code of Civil Procedure. Art. 300.
- Brazil. Decree-Law No. 3,689, of October 3, 1941. Code of Criminal Procedure. Arts. 312 and 313.
- STF. Súmula 625: "Controversy over a matter of law does not prevent the granting of a writ of mandamus".
- STJ. AgInt in AREsp 1,845,230/SP, Rel. Min. Raul Araújo, Fourth Panel, judged in 2023.
- Calamandrei, Piero. Introduzione allo studio sistematico dei provvedimenti cautelari. Padova: CEDAM.
- Didier Jr., Fredie. Curso de Direito Processual Civil: Teoria da prova, direito probatório, ações probatórias, decisão, precedente, coisa julgada e tutela provisória. Vol. 2. Juspodivm.
