Maximilien Robespierre was nicknamed among his co-religionists "The Incorruptible" for embodying, it was said, the integrity of revolutionary virtue in its most inflexible expression. For others, and also after his fall and his death for some who had supported him in his day, he was simply a monster of the vein, responsible for countless political murders. Someone, then, in whom virtue was monstrous or monstrosity virtue. He was undoubtedly the most influential and powerful man during the period of the French Revolution known as the Terror, and trying to understand how an obscure provincial lawyer was able to achieve this requires both probing his personality as much as possible, and the various elements that came into play during the Revolution. The resources that he used and the ideas that he advocated and with which so many identified. Ideas and resources that were not only the product of his time, but also hanged some of the mechanisms of revolutionary politics in the contemporary world. Robespierre. The virtue of the monster, the first book by a Spanish author who thoroughly treats his figure with an academic approach, thus combines a biographical study, analysis of political ideas and interpretation of the historical context.