Abstract
The civil contentious proceedings is governed by the principle to hear, which is an expression of the parties' liability for the outcome of the proceedings. With few exceptions, the procedure by which the court will ex officio investigate the facts of the case is not admissible in the contentious proceedings.
Nor is it permissible for the court itself to seek appropriate evidence to verify its assumptions of that fact. The aim of the paper is to analyze the principle to hear in civil contentious proceedings and to define it against the principle to investigate, which is decisive for non-contentious proceedings.
In conclusion, the author summarizes the acquired knowledge based on the analysis of the problem.