CLAUBERG, JOHN, born at Salingen, in the duchy of Berg, in 1622, professed philosophy and theology, first at Herborn, and afterwards at Duisburg, where he died on the 31st January 1665. He was one of the first who taught in Germany the doctrine of Descartes, which he had studied under John Ray at Leyden. His philosophical works (Opera Omnia Philosophica), collected at Amsterdam by John Theodore Schalbruch, in two volumes 4to, with a life of the author prefixed, by John Christian Hennius, show how well he was qualified to appreciate the merits of the French philosopher, and to follow in his footsteps. The most esteemed of Clauberg's works is his Logica Veteris et Nova; but he has not admitted in this collection a little work, entitled Ars Etymologica Teutonum e Philosophia fontibus derivata, published by him at Duisburg in 1668, in 8vo, and which Morhof has highly commended in his Polyhistor, and Leibnitz included in his Collectanea Etymologica. This brochure was intended as the prelude to a large work, De Causis Linguae Germanicae, which, however, the projector did not find leisure or encouragement to execute. In a separate form we have collected J. Claubergii et Martini Hendii Dissertationes selectae, quibus controversiae fidei adversus omnis generis adversarios explicantur, and J. Claubergii et Tobiae Andreae Exercitationes et Epistolae varii argumenti.