Among the writers who have transmitted to us the history of those memorable wars, which, for a space of nearly two centuries, unceasingly depopulated Europe, in order to carry destruction and desolation throughout the finest regions of Asia and Africa, there is scarcely one who does not make mention of that barbarous horde, which, established in a corner of Syria, and known by the name of Assassins, rendered itself formidable both to the orientals and occidentals, and exercised its atrocities indifferently against the Moslem sultan and the Christian prince. If the historians of the Crusades have mingled a few fables with the information which they have handed down to us, regarding the tenets and manners of these sectarians, we ought not to feel surprised; for the terror which they inspired, scarcely permitted our warriors to search very deeply into their origin, or to procure exact data concerning their religious and political constitution. Even their name has been disfigured and presented under a multitude of different forms, and it is to this that we must attribute the uncertainty of modern critics as to its origin and etymology. Among all the writers who have devoted their attention to historical and critical researches into the subject of the Assassins, none has shed more light upon it than M. Falconet. Nevertheless, as this learned gentleman had not applied himself at all to the study of the languages of the east, and could not, therefore, avail himself, in his inquiries, of the assistance of the Persian and Arabian writers, whose works had never been either published or translated, he has not been able to trace the Assassins up to their true origin, nor to give the etymology of their name. It is to supply this defect in his labours that I have decided upon treating this subject anew. In a dissertation, which I submitted to the judgment of the _classe_, and of which I shall present you with a short analysis, I proposed to inquire, what was the doctrine of this sect, and by what ties they were related to one of the principal divisions of Mohammedanism; and, lastly, why they had received a name, which, passing with a slight change into the west, has furnished several modern languages with a term expressive of a cool premeditated murder.