Abstract

Descartes describes in the Discours de la méthode his stay in Germany in winter 1619/20 as decisive for his intellectual development. In Germany he was especially interested in the mathematics of German reckoningmasters and mathematical practitioners. Frustrated from their form of representation, from their mathematical „style”, he began to create his own, which he considered a first step in the development of his method in order to secure true knowledge. Descartes could derive additional confirmation for his task by the mentalities of orthodox and heterodox protestantism. He learned that Johannes Faulhaber one of the leading German mathematicians had strong connections to the rosicrucian movement, a very popular form of heterodox protestantism. The convictions and aims of the supporters of the rosicrucian movement in part agreed with and in part contradicted seriously those of Descartes, whereas the arguments of the orthodox protestants in their fight against the rosicrucian movement interacted positively with the ideas of Descartes. The reaction of Descartes to his encounter with German protestantism offers an important element for the explanation of the strong positive and negative reactions to Cartesianism in protestant countries, especially in the Netherlands