Bloch focuses the question of the historical comment in which it suggests that the historian is disabled to evidence the studied facts even so and therefore that in the study of the recent fact, bigger possibilities of understanding are had, the certifications in any time is indispensable, in the present time, the original vestiges clearly in its return, as to gain body and life for the manipulation of the researcher, therefore, ' ' The diversity of the historical certifications is almost infinite. Everything that the man says or writes, everything whom it manufactures, everything that touches can and must inform on ele.' ' (Bloch 2001:79 p). In the historical research, the historian limits it the stories of the certifications, due to impossibility of the historian to testify the studied facts, therefore they already will happen, therefore she is invariant and its knowledge can gradual and be perfected. During the historical research, the historian must have persistence, understanding that he has two types of documents in will be able to find: explicit, that they are manufactured, and the implicit ones that he does not appear spontaneously in the reproduction of these documents in the anonymity. Bloch innovates when saying that the historian does not have to use only written documents, but to also work the certifications not written, of other sciences, in particular of archaeology, in the sample that the past will be always in process and progressing, changing many times its way to analyze it and to understand it, and that the vision of each historian and even though interpreted could in accordance with be written in differentiated way differently depending reading it. The position of the historian must be of questioning to perceive the contradictory in certain authors, what they had most of the time taken inquiries to the weak ones, therefore ' ' The archaeological, exactly apparent the clearer and complacentes ones texts or documents, do not say seno when we know interrog-lo' ' (Bloch 2001:79 p).