Since the entry into force of the Code of Civil Procedure, procedural law scholarship has not succeeded in developing and establishing an independent doctrine of the procedural act. The question of the legal nature of the procedural act remains unanswered to this day. In the sense of a return to the doctrine of declarations of intent, Jürgen Stamm shows that this doctrine can be applied in the same way in civil proceedings. On the basis of the relevant statutory foundations, the supposed procedural act proves to be a procedural declaration of intent. Its prototype is the statement of claim; its counterpart on the defendant's side is the withdrawal of the action as a permissible revocation of the claim. The purported peculiarities of statements made in litigation-namely their resistance to conditions and revocation-find their substantive law counterpart in the protection afforded to the recipient of a unilateral declaration. Legal certainty in proceedings is not achieved by denying the possibility of avoiding procedural declarations for mistake; rather, it is achieved by observing the strict requirements applicable to such avoidance. The civil law doctrine governing the legal consequences of defects can be transferred to procedural declarations. Procedural declarations with a dual nature, when differentiated according to their respective addressees, prove to involve an overlap between a procedural declaration addressed to the court and a substantive law declaration of intent addressed to the opposing party. Ultimately, Jürgen Stamm integrates the previously heterogeneous conglomerate of problems surrounding so-called procedural acts into a uniform legal framework and presents a self-contained, holistic model of solutions.