Johannes Clauberg, a German Cartesian philosopher, was born in Soligen, February 24, 1622, and died in Duisburg, January 31, 1665. Though he lived a short life, his philosophical output was considerable; his name became almost synonymous with that of René Descartes in Germany. Clauberg studied in Cologne and Bremen, where he came under the influence of reformed scholasticism and the pedagogical and methodological ideals of Jan Amos Comenius. At Bremen he also met Tobias Andreae, whom he later joined in Groningen in 1644 after Andreae was appointed professor of History and Greek. He disputed some theses in 1646 and published his first independent treatise, Ontosophia, in 1647. Clauberg's initial works, including Ontosophia, do not display the influence of Descartes's philosophy, though Clauberg rewrote the book along Cartesian lines in later editions. After travels to France, to the Protestant Academy in Saumur and Paris (where he seems to have met some early...