The hermeneutic construction of the writ of injunction by the Supreme Federal Court

Perspectives on the separation of powers and judicial activism

Abstract

This study analyzes the constitutional nature of the *Mandado de Injunção*—a legal remedy designed to enable the exercise of constitutional rights and freedoms guaranteed by norms of limited efficacy when such exercise is obstructed by legislative failure to enact implementing regulations. It examines how the Supreme Federal Court (STF) has shaped the effects of this remedy through its rulings, outlining the nature of the instrument and the prevailing schools of thought regarding it, while highlighting the STF's current "concretist" approach. Consequently, the study addresses the alleged conflict between the principle of separation of powers and the principle of constitutional effectiveness, arising from judicial activism—a practice for which the judiciary is often accused of usurping the legislative function by engaging in political action. This is a bibliographic and doctrinal study that includes a brief analysis of relevant case law. Finally, it evaluates the importance of judicial activism in making the *Mandado de Injunção*—and, by extension, the Constitution itself—truly effective. The study concludes that judicial activism yields positive results for the legal system, provided it respects constitutional limits; otherwise, instead of offering a solution, it risks becoming a problem.