This book critically addresses one of the most complex issues in procedural law: the objective limits of res judicata. Particularly relevant in civil law countries such as Italy and Germany-and especially in Portugal-this topic has generated intense doctrinal debate. In an effort to circumvent the constraints imposed by the traditional model of the plea of res judicata and the triple identity test, Portuguese legal scholarship developed the concept of the authority of res judicata. However, the vague contours of this concept have led to doctrinal uncertainty and inconsistency.

Does res judicata extend only to the operative part of the judgment, or does it also encompass its reasoning? Is only the claim precluded, or also the cause of action? Which issues that arise during litigation are barred from future disputes? The more freedom allowed to relitigate such issues, the less legal certainty the decision provides. Conversely, the more stabilizing the decision, the narrower the scope for future litigation.

This work proposes an alternative to the perplexing approaches that have challenged jurists within the Romano-Germanic tradition-particularly in Portugal: res judicata should also extend to prejudicial questions, provided they were effectively litigated by the parties, with full procedural guarantees, and expressly decided. This proposal reflects an adaptation of the Anglo-American model of collateral estoppel, already partially adopted by Brazilian legislation, with a powerful pacifying effect.

The monograph is divided into three parts. The first examines the Anglo-American model of stabilizing judicial decisions, from the pre-Roman influence on res judicata to the Restatement (Second) of Judgments, including the requirements of nonmutual collateral estoppel, partially incorporated into Brazilian law. The second part explores the core concepts of the controversy-main and prejudicial issues, preclusion, res judicata, authority and plea of res judicata-and presents the tension between legal certainty and freedom at the heart of the fundamental right to res judicata, drawing on a profound insight by Zygmunt Bauman.

Ultimately, this book argues that its proposed framework offers a constitutionally sound interpretation of the fundamental right to res judicata, striking a careful balance between the prohibition of excessive restriction and the need to avoid insufficient legal protection. The third and final part turns to the procedural topology of res judicata-exploring where, within the complaint, defense, and judgment, the preclusive effect truly resides: whether in the claims, the causes of action, the operative part, or the reasoning. It also revisits the historic debate between Savigny and Chiovenda, suggesting that their positions may be more compatible than traditionally assumed. The analysis concludes that the subject matter of the dispute encompasses not only the principal issue but also the prejudicial questions that were effectively litigated, offering a critical perspective on the Italian legislative model, later adopted in Portugal and formerly in Brazil's Code of Civil Procedure.

Autorentext

Gustavo Baini holds a Bachelor of Laws (LL.B.) from UFPel (2006), supervised by Prof. Dr. Roger Raupp Rios; a Postgraduate Specialization in Public Law from Escola Superior Verbo Jurídico (2009), under the guidance of Prof. Dr.ª Vânia Hack de Almeida; a Master's degree in Law from UFRGS (2012), advised by Prof. Dr. Almiro do Couto e Silva, with a defense panel composed of Professors Dr. Humberto Ávila, Dr. Ingo Sarlet, and Dr. Itiberê Oliveira; and is currently a Ph.D. candidate in Law at the Faculty of Law of the University of Lisbon, under the supervision of Prof. Dr.ª Paula Costa e Silva and co-supervision of Prof. Dr. Daniel Mitidiero. Affiliated with the Judicial School of the Regional Labor Court of the 4th Region (TRT4), he coordinates the Study Group on Jurisprudential Analysis and is a member of the Study Group on the Draft Labor Procedure Code. Professionally, he has served as a professor at the Faculty of Law of UFPel (2007-2009), autonomous attorney (2007-2009), judicial clerk to a Labor Appellate Judge at TRT4 (2009-2015), legal advisor to a Federal Labor Prosecutor (2015-2020), Director of the Appeals Secretariat at TRT4 (2020-2023), and currently serves as Advisor to the Office of the President of TRT4 (2023-). He is also a member of the Precedent and Class Action Management Unit and the Court's Intelligence Center (2020-2024), as well as the Judicial Cooperation Unit (2024-). He lectures in postgraduate programs, judicial schools, and the Escola Superior da Advocacia (since 2021). His scholarly work includes articles published in Revista da AJURIS, Revista do Processo, Revista de Legislação Trabalhista, Revista de Direito do Trabalho, Revista da Escola Judicial do TRT da 4ª Região, and Consultor Jurídico (ConJur). He is the author of the book Teoria da Mutação Constitucional e a Jurisprudência do Supremo Tribunal Federal, published by Editora Dialética in 2021.