It sheds light on the differential oratorical characteristics of Catholic preaching (principally Jesuit) in the XVIIth century in comparison with classical rhetoric, from the starting point of a corpus of French and Portuguese orators. Three characteristics emerge : constant reference to the Bible (by way of the Vulgate), a relationship to history which closely associates Biblical History and profane history, and an imperative for simplicity aiming at immediate effectiveness of the message for the conversion of hearts.