Friedrich Karl Christian Ludwig Büchner (29 March 1824 – 30 April 1899) was a German philosopher, physiologist and physician who became one of the exponents of 19th-century scientific materialism. Biography Büchner was born at Darmstadt on 29 March 1824. From 1842 to 1848 he studied physics, chemistry, botany, mineralogy, philosophy and medicine at the University of Giessen, where he graduated in 1848 with a dissertation entitled Beiträge zur Hall'schen Lehre von einem excitomotorischen Nervensystem (Contributions to the Hallerian Theory of an Excitomotor Nervous System). Afterwards, he continued his studies at the University of Strasbourg, the University of Würzburg (where he studied pathology with the great Rudolf Virchow) and the University of Vienna. In 1852 he became lecturer in medicine at the University of Tübingen, where he published his magnum opus Kraft und Stoff: Empirisch-naturphilosophische Studien (Force and Matter: Empiricophilosophical Studies, 1855). Büchner was one of the founding members of the Freies Deutsches Hochstift (Free German Foundation). According to Friedrich Albert Lange (Geschichte des Materialismus, 1866), Kraft und Stoff was imbued with a fanatical enthusiasm for humanity. Büchner sought to demonstrate the indestructibility of matter, and the finality of physical force. The scientific materialism of this work, which contemporaries often lumped together with the publications of other 'materialists' like Karl Vogt and Jacob Moleschott, caused so much opposition that he was compelled to give up his post at Tübingen, and he retired to Darmstadt. He practiced as a physician and contributed regularly to pathological, physiological and popular magazines. He continued his philosophical work in defense of materialism, and published Natur und Geist (Nature and Spirit, 1857), Aus Natur und Wissenschaft (From Nature and Science, vol. I., 1862; vol. II., 1884), Der Fortschritt in Natur und Geschichte im Lichte der Darwinschen Theorie (Progress in Nature and History in the Light of the Darwinian Theory, 1884), Tatsachen und Theorien aus dem naturwissenschaftlichen Leben der Gegenwart (Facts and Theories in the Scientific Life of Present, 1887), Fremdes und Eigenes aus dem geistligen Leben der Gegenwart (Strangers and Selves in the Spiritual Life of the Present, 1890), Darwinismus und Socialismus (Darwinism and Socialism, 1894), Im Dienste der Wahrheit (In the Service of Truth, 1899). Ludwig Büchner's materialism was the founding ground for the freethinkers' movement in Germany. In 1881 he founded in Frankfurt the "German Freethinkers League" ("Deutsche Freidenkerbund"). He died at Darmstadt on 30 April 1899. Philosophical work In estimating Büchner's philosophy it must