The contribution examines the course and outcome of Professor Bonnet’s studies on the documentary process. The focus is on the nature of this process, which does not belong to the group of summary processes, but to the ex-notorio processes. In fact, it is entirely determined by the evidence that the legislator has decided to use as a basis. On this basis, the peculiarities of the documentary process are explained, especially the postponement to ordinary proceedings in the event that the evidence is not confirmed. The reason for Professor Bonnet’s interest in the documentary process is his conviction that by divine right, a more onerous procedure should not be imposed to ascertain the nullity of a marriage when the circumstances allow for its simplification. The author shows in the contribution how Professor Bonnet’s elaboration on the documentary process corresponds structurally and, in some cases, also literally to the understanding of the processus brevior inaugurated in the recent reform of the process of matrimonial nullity with the motu proprio Mitis Iudex Dominus Iesus.