This book is an intellectual biography of Johann Friedrich, who was one of the most famous philosophers in early 19th century Germany. Herbart was trained in the German idealist tradition under Fichte, but he eventually broke with Fichte and major idealist doctrines. 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 (viz. the dualism between essence and existence, reason and sensibility). While Herbart still retained elements of idealism, he was more realistic than his idealistic counterparts, maintaining that elements of the sensible manifold were given rather than posited by the mind. 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.