DRIESCH, HANS. - Biologist and philosopher, b. at Kreuznach on 28 Oct. 1867, d. on 16 Apr. 1941. He studied at Hamburg, Freiburg, Munich and Jena, where he took his degree (1889) in natural sciences.
He was a disciple of Haeckel, but soon moved away from him and formed a friendship with G. F. Wolff and W. Roux. From 1891 to 1900 he worked at the Zoological Station of Naples and then went to Heidelberg, where in 1911 he became professor of philosophy. In 1920 he taught natural philosophy at Cologne and in 1921 he was appointed professor at Berlin. He traveled a great deal in China and America and obtained various honorary degrees and recognitions from many academies.
He began his scientific activity under the guidance of Haeckel, but later, though influenced by the teaching of Wolff and Roux, he became the champion of dynamic vitalism. His doctrine that the functions of protoplasm cannot be explained mechanically was the consequence of his results on the regulativity of sea-urchin eggs, which demonstrated how isolated blastomeres can give rise to complete embryos.
On the basis of these experiments he concluded that the organism must be an equipotential harmonic system possessing an individualizing vital "entelechy" that works through matter with a vision of the complex. His animatomechanism in the psychological sphere is expressed in Philosophie des Organischen (2 vols., Leipzig 1909), Analytische Theorie der organischen Entwicklung (ibid. 1894), Science and philosophy of the Organism (Gifford lectures 1907-1908), History and theory of vitalism (1914), The problem of individuality (1914), Wissen und Denken (Leipzig 1919), Leib und Seele (ibid. 1920).
Together with W. Roux he founded developmental mechanics, which today is more properly called, after G. F. Wolff, developmental physiology. D.'s vitalist conception is much contested today.