The ad hominem argument, although rhetorical and logical in origin, has a transversal incidence in Law, manifesting primarily in Criminal and Constitutional Procedure as an argumentative fallacy that shifts the refutation of the merits of the case to the personal disqualification of the interlocutor, directly affecting the principles of due process of law and human dignity.
Concept and Foundation
The term ad hominem (Latin for "to the man") designates an argumentative technique that seeks to invalidate a legal or factual proposition not through logical or evidentiary counter-argumentation, but through a direct attack on the honor, reputation, or personal condition of the subject making it. Within the scope of legal hermeneutics, such practice is proscribed, as the system of procedural guarantees requires that procedural dialectics remain focused on the object of the dispute (res in iudicium deducta).
The legal nature of the institute, when transposed to the procedural environment, does not qualify as a legitimate means of proof or defense, but as a stain on forensic ethics and a flaw in reasoning. The use of personal attacks in petitions or oral arguments subverts the purpose of the process, which should be an instrument for the pursuit of procedural truth and the application of justice, rather than a stage for the degradation of the lawyer, the member of the Public Prosecutor's Office, or the magistrate.
Historical Origin and Evolution
The genesis of the ad hominem fallacy dates back to Aristotelian rhetoric; however, its systematization in modern Law stems from the transition from the inquisitorial to the adversarial system. In Comparative Law, the Anglo-Saxon tradition, through the rules of evidence, has always limited the use of "character attacks" (character evidence), allowing them only in strict situations regarding witness credibility. In the Brazilian legal system, doctrinal evolution has consolidated the understanding that the process must be governed by impersonality and mutual respect, under penalty of violating the statute of the legal profession and the duties of urbanity provided for in Law 8.906/1994.
Legal Provision and Framework
The national legal system does not classify ad hominem as a procedural institute, but represses it through mandatory rules of conduct and protection of honor:
- Federal Constitution (CF/88): Art. 5, items X (protection of honor) and LV (adversarial system and full defense).
- Code of Civil Procedure (CPC/15): Art. 77, which imposes the duty of urbanity on the subjects of the process.
- Statute of the Legal Profession (Law 8.906/94): Art. 31 and Art. 33, which impose on the lawyer the duty to maintain dignity and urbanity, prohibiting the use of injurious expressions.
- Code of Criminal Procedure (CPP): Art. 251, which grants the judge police power to maintain order and decorum in hearings.
Jurisprudence and Practical Application
The jurisprudence of the Superior Courts (STF and STJ) has repeatedly repudiated the use of ad hominem strategies in procedural documents. The consolidated understanding is that the professional immunity of the lawyer (art. 7, § 2, of Law 8.906/94) is not absolute, not reaching offenses that transcend technical criticism and affect the subjective honor of magistrates or opposing parties.
Recently, the STJ has reinforced in rulings by Criminal Panels that the personal disqualification of the accuser or the magistrate, instead of addressing the materiality and authorship of the crime, constitutes an abuse of rights, which may lead to disciplinary sanctions with the OAB (Brazilian Bar Association) and, in extreme cases, the exclusion of injurious excerpts from the case files (risk of ineptitude due to excessive language).
Related Principles and Divergences
The fight against ad hominem directly dialogues with the principles of procedural good faith (art. 5 of the CPC) and cooperation. Contemporary doctrine distinguishes vehement criticism — legitimate in the exercise of full defense — from the ad hominem attack. The doctrinal divergence often lies in the boundary between the right to criticize a judicial decision (freedom of expression) and disrespect for authority, with the dividing line being the presence of elements that exclusively aim to denigrate the image of the public agent to the detriment of technical reasoning.
Contemporary Relevance
Currently, the practice of ad hominem takes on digital contours, with the exposure of magistrates and lawyers on social networks, which directly impacts the independence of the Judiciary. Jurisprudence has understood that such conduct, when mirrored in lawsuits, constitutes an attempt at intimidation (chilling effect), and it is the duty of the magistrate, in the exercise of police power, to prohibit the continuation of any argumentation that is not limited to the merits of the legal controversy. Doctrinal rigor dictates that Law must remain the empire of reason (logos), and not the empire of passions or personal offenses.
Legal and Jurisprudential References
- BRAZIL. Law No. 8.906, of July 4, 1994. Statute of the Legal Profession and the Brazilian Bar Association.
- BRAZIL. Law No. 13.105, of March 16, 2015. Code of Civil Procedure.
- STF. ADI 1127-8/DF. Rapporteur Justice Marco Aurélio. (Precedent on professional immunity and limits of criticism).
- STJ. RHC 142.345/SP. (Discussion on excessive language and the dignity of the process).
- CODE OF ETHICS AND DISCIPLINE OF THE OAB. Resolution No. 02/2015.
