Summary — I. Preparation of the text on the ordinary magisterium of the Roman Pontiff. 1. Indications of the preconciliar consultation. 2. The Scheme of the preparatory theological Commission. II. The text on the ordinary magisterium of the Roman Pontiff submitted to the Council. 1. The judgement of the Council Fathers on the text of the preparatory Commission. 2. The text on the ordinary magisterium of the Roman Pontiff in the new Scheme about the Church. 3. The discussion of the text. 4. The revision of the text. 5. Voting and final evaluation of the text. III. The promulgated text. 1. Nature of the pontifical magisterium «non ex cathedra ». 2. Nature of the obedience due to the pontifical magisterium «non ex cathedra ». 3. Possible limitations of such obedience.