FORTLAGE, KARL (1806-1881), German philosopher, was born at Osnabrück. After teaching in Heidelberg and Berlin, he became professor of philosophy at Jena (1846), a post which he held till his death. Originally a follower of Hegel, he turned to Fichte and Beneke (q.v.), with whose insistence on psychology as the basis of all philosophy he fully agreed. The fundamental idea of his psychology is impulse, which combines representation (which presupposes consciousness) and feeling (i.e. pleasure). Reason is the highest thing in nature, i.e. is divine in its nature, God is the absolute Ego and the empirical egos are his instruments.
Fortlage's chief works are: Genetische Geschichte d. Philos. seit Kant (Leipzig, 1852); System d. Psych, als empirische Wissenschaft (2 vols., Leipzig, 1855); Darstellung und Kritik der Beweise für das Dasein Gottes (Heidelberg, 1840); Beiträge zur Psych. als Wissenschaft (Leipzig, 1875).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)