Though little known today, Johann Friedrich Herbart was one of the leading philosophers of his age, the competitor of Schelling and Hegel. Although he was trained by Fichte, Herbart soon became a critic of the idealist tradition and developed a philosophy antithetical to it. His own philosophy was opposed to the idealist tradition in important respects: he defended a dualism between the factual and normative; he was an ontological pluralist rather than monist; and he accepted crucial Kantian dualisms that had been rejected by the idealists. Herbart was also an important forerunner of analytic philosophy, first in breaking with the idealist tradition, and second in insisting that the proper method of philosophy is the analysis of concepts rather than speculation about the universe as a whole. In the first intellectual biography of Herbart in English, Frederick C. Beiser studies the development of one of 19th-century Germany’s most important philosophers, from his education in Oldenburg and Jena to his final years in Goettingen.