Rudolf Hermann Lotze (born May 21, 1817, Bautzen, Saxony [Germany]—died July 1, 1881, Berlin) was a German philosopher who bridged the gap between classical German philosophy and 20th-century idealism and founded Theistic Idealism.
While studying for doctorates in medicine and philosophy at the University of Leipzig (1834–38), he began interpreting physical processes as essentially mechanistic. After a short medical practice, he concentrated his efforts on philosophy by teaching at Leipzig (1842–44) and becoming professor of philosophy at the universities of Göttingen (1844–80) and Berlin (1881).
He first became known as a physiologist in his polemic against vitalism. Although he regarded physical and psychic sciences equally, he espoused a natural order to the creation of the universe as determined by a supreme being. His religious philosophy affected modern thought by emphasizing the problem of delineating value from existence. The foundation for his theories is documented in Logik (1843), Mikrokosmos, 3 vol. (1856–64), and Metaphysik (1879).