Fischer, ERNST KUNO BEERTHOLD, the son of a country pastor, was born in the Silesian village of Sandewalde, July 23, 1824. From the Posen gymnasium he passed to the university of Leipzig, where he attended lectures on philology and theology; but after his first session he went to Halle, and here, under the influence of Erdmann and Schaller, becoming interested in philosophy, he resolved to devote himself to this as his life-study. He took his Ph.D. degree in 1847, and in 1850 established himself at Heidelberg as a privatdozent of philosophy. His eloquence and his poetical sympathies, in addition to his actual knowledge of philosophy, now stood him in good stead. Students came in flocks to hear him, and his enormous popularity, resulting from his enthusiasm, deep insight, and clearness of exposition, increased steadily. Suddenly, however, in July 1853, presumably because of private charges of pantheism made against the first volume of his History of Modern Philosophy, the Baden government without any explanation deprived him of his position as privatdozent. During three years of academic exile that followed, Fischer lived quietly with kindred spirits amid the beautiful surroundings of Heidelberg, and continued meantime to work at his History, publishing between 1853 and 1856 the volumes on Spinoza, Leibnitz, and Bacon. In 1856 he received a call to Fichte's old chair of philosophy at Jena; and in Jena he laboured for sixteen years. At last, in 1872, when Edward Zeller succeeded Trendelenburg at Berlin, Fischer—all practical difficulties in connection with the freedom of lecturing having now disappeared—obtained Zeller's post at Heidelberg.
Fischer's chief work is his great history of modern philosophy, Geschichte der Neuern Philosophie (1852-77; new ed. 1889-90). The parts treat respectively of (1) the Cartesians and Spinoza, (2) Leibnitz, (3) Bacon and his successors, (4) Kant, (5) Fichte, (6) Schelling, (7) Schelling to Schopenhauer, unfinished in 1893, (8) Schopenhauer. Fischer's historical books seek to do for modern philosophy what Zeller's do for old-world systems. His other great philosophical achievement is his System der Logik und Metaphysik (1852; new ed. 1865), in which, while he adheres in the main to Hegel's position, he yet criticises Hegel severely on many important points. Of his other philosophical writings the most noteworthy is a Critique of Kant, which, like Bacon and Descartes and his School, has been translated into English. Other works deal with Goethe's Faust, Iphigenia, and Tasso, Lessing, Schiller, the history of Heidelberg, free-will, &c. See a monograph by Falkenheim (1892).