A German philosopher, savant, jurist, historiographer and diplomat, a universal spirit in contact with the whole of the learned Europe of his time. The apex summit of rationalist intellect, the system he proposed had the ambition of overcoming the religious and philosophical divisions within Christianity, harshly experienced through the wars of religion. The framework of Leibniz’s thinking was logic and mathematics. After discovering differential calculus, he invented, independently of Newton, infinitesimal calculus and made mathematics in general progress very widely, as a tool at the service of the other areas of knowledge. Leibniz, who deplored the divisions within the Germanic Holy Roman Empire, fractured into a mosaic of little states, appealed for the cultural renaissance of his homeland and advocated the creation of a German Society of Arts and Sciences. The savant, who wrote the majority of his oeuvre in French, was given responsibility in 1672 for an ambitious diplomatic mission at the instigation of the Elector of Mainz: it consisted of diverting against Egypt – thus against the Turks – the conquest ambitions of Louis XIV, the King of a France which was dominant at this epoch. The project aborted, but his stay in France, intercut with voyages to England, was taken advantage of to establish numerous scientific and philosophical contacts from which he would draw the lessons in exhorting the Germans to ‘better cultivate their reason and their language.’