The principle of isonomy, a fundamental pillar of Constitutional Law and a guiding force for the entire Brazilian legal system, embodies material equality among individuals before the State. Its primary purpose is to ensure that those who are unequal are treated according to their inequalities, mitigating arbitrary disparities and guaranteeing distributive justice in legal relations.
Concept and Foundation
Isonomy, or legal equality, is not to be confused with arithmetic or absolute equality. From the perspective of contemporary legal dogmatics, the principle requires that the legislator and the law enforcer consider the specificities of each situation, granting differentiated treatment only when there is a legitimate and reasonable basis. The legal nature of this institute is that of a fundamental principle, possessing direct and binding normative efficacy over all constituted powers.
Classical doctrine, led by Celso Antônio Bandeira de Mello, establishes that isonomy prohibits the creation of arbitrary distinctions, requiring that the factor of discrimination — the element used to differentiate situations — maintains a logical correlation with the purpose of the norm. Therefore, material equality presupposes the overcoming of historical and social barriers, serving as the engine for affirmative action and social protection policies.
Historical Origin and Evolution
Historically, isonomy evolved from the liberal concept of "equality before the law" (formal isonomy), originating from 18th-century constitutionalism (Declaration of the Rights of Man and of the Citizen, 1789), to the contemporary conception of "equal opportunity" and "substantive equality." In Comparative Law, the Equal Protection Clause of the 14th Amendment to the United States Constitution served as a paradigm for protection against discriminatory legislation. In Brazil, this evolution was consolidated by the transition from the liberal model to the Social State of Law, culminating in the promulgation of the 1988 Federal Constitution (CF/88).
Legal and Constitutional Provision
The epicenter of isonomy in the Brazilian legal system is found in Article 5, caput, of the Federal Constitution, which prescribes: "All are equal before the law, without distinction of any kind." This norm has specific developments in various provisions, such as:
- Art. 5, item I: Equality between men and women in rights and obligations.
- Art. 7, item XXX: Prohibition of salary differences based on sex, age, color, or marital status.
- Art. 37, item II: Requirement of a public competitive examination, ensuring equal access to public offices.
Practical Application and Jurisprudence
The Supreme Federal Court (STF) has consolidated the understanding that isonomy authorizes unequal treatment to compensate for imbalances. Notable examples include the constitutionality of racial quotas in universities (ADPF 186) and the extension of social security and labor rights to historically marginalized groups.
Within the scope of the Superior Labor Court (TST), Súmula nº 6, which deals with salary equalization, is the most recurring practical application of isonomy in private relations. Current jurisprudence prohibits distinctions that lack support in objective technical criteria of productivity or technical perfection, as provided for in Art. 461 of the Consolidation of Labor Laws (CLT).
Related Principles and Doctrinal Divergences
Isonomy walks pari passu with the principles of Reasonableness and Proportionality. Contemporary doctrinal divergence lies in the tension between "positive discrimination" (affirmative action) and the principle of state neutrality. Legal-philosophical currents, based on the work of Ronald Dworkin, argue that egalitarian treatment sometimes requires the State to intervene actively to ensure that everyone possesses the same basic resources, going beyond the simple prohibition of discrimination.
Contemporary Relevance
Currently, isonomy faces new challenges brought about by technology and automation. Debates regarding algorithmic bias in judicial decisions and personnel selection processes demonstrate that equality must be protected even in the virtual space. Protection against algorithmic discrimination has become one of the most relevant topics for 21st-century constitutional hermeneutics, requiring the Law to apply the principle of isonomy to prevent prejudiced biases from being automated on a large scale.
Legal and Jurisprudential References
- BRAZIL. Constitution (1988). Constitution of the Federative Republic of Brazil. Brasília, DF.
- BRAZIL. Decree-Law No. 5,452, of May 1, 1943. Approves the Consolidation of Labor Laws (CLT).
- STF. ADPF 186/DF. Rapporteur: Justice Ricardo Lewandowski. Judged on 04/26/2012.
- TST. Súmula No. 6: Salary equalization. Art. 461 of the CLT.
- BANDEIRA DE MELLO, Celso Antônio. O Conteúdo Jurídico do Princípio da Igualdade (The Legal Content of the Principle of Equality). 3rd ed. São Paulo: Malheiros, 2018.
