Objective Limits of Res Judicata

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.