Baron Gottfried Wilhelm von Leibnitz (more correctly Leibniz) was a German philosopher and mathematician, born in Leipzig and educated in Leipzig, Jena, and Altdorf where he graduated in 1666. He was in the service of the archbishop elector of Mainz from 1667-76, then spent four years in Paris and London, meeting many scholars. He discovered and published, in 1684, new notations of calculus before Newton, thus causing much, long-debated controversy. While in the service of the Duke of Brunswick as librarian and privy councilor, he wrote Systema Theologicum, an attempt to find a common ground for the Catholic and Protestant faiths. Leibnitz spent the last thirty years of his life in the study of mathematics, natural science, philosophy, theology, history, law, politics, and other subjects. He composed most of his philosophical works, chiefly as essays, treatises, etc., during these later years. He left no complete and finished exposition of his philosophy (Leibnitzianism). His principal work in theology, Théodicé (1710), in the main a discussion of the problem of evil and a defense of optimism, was ridiculed by Voltaire in Candide.