576 



SCIENCE 



[N. S. Vol. XXXVIII. No. 982 



cause of its enthusiastic efforts to reform 

 and to conquer the natural science of its 

 time, it gave to these old ideas a new turn, 

 a new setting, a new application, a new 

 translation. The Naturphilosophie sup- 

 posed itself to be interpreting the world of 

 natural science in the light of its own 

 philosophical ideas. As a fact, it was 

 rather interpreting certain ancient philo- 

 sophical ideas in the light of the facts 

 which it learned in the course of its rather 

 undisciplined study of science. But by 

 thus reshaping the old ideas into modern 

 forms, it prepared them to become leading 

 ideas for a later generation of serious sci- 

 entific workers. For, when it thus trans- 

 lated them into more modern terms, it 

 rendered them comprehensible and attrac- 

 tive to men of the new time. It made them 

 seem portentous to its own generation. 

 The Naturphilosophie itself was soon dead, 

 and mouldering in the grave. These lead- 

 ing ideas, its soul, went marching on. 



I have now enumerated three of the 

 leading ideas of the Naturphilosophie. 

 You will properly ask what evidence there 

 is that leading ideas derived from such 

 sources actually influenced any serious sci- 

 entific workers of a later period. 



And so I come, hereupon, to a very in- 

 adequate report of an interesting class of 

 phenomena, whose significance the his- 

 torians of the nineteenth century science 

 seem to me to have somewhat neglected. 

 Let me call your attention to the following 

 biographical facts regarding a number of 

 notable scientific men. 



Johannes Miiller, the physiologist, born 

 in 1801, studied from 1819 to 1822 in 

 Bonn. His most notable teachers in medi- 

 cine were Naturphilosophen in tendency. 

 Bonn was then a center of medical Natur- 



philosophie. Miiller later rejected the 

 philosophy in question — how vigorously I 

 need not tell you. But he always remained 

 in spirit, as I have understood from the 

 authorities, in the better sense a distinctly 

 philosophical physiologist. He abandoned 

 speculation, but he did not abandon syn- 

 thesis. His Habilitationsschrift in 1830, at 

 Bonn, related to embryology, which also 

 received other contributions from him. 

 His great work on physiology is a syn- 

 thetic one. He always viewed his special 

 work in its relations to the whole medical 

 science. His influence was in the direction 

 of unity as weU as of thoroughness. 

 Amongst his pupils were Helmholtz, Du 

 Bois Reymond, Schwann and Virchow — 

 all of them men of a distinctly philosoph- 

 ical universality of grasp. 



J. L. Schonlein, born in 1793, studied 

 in Wiirzburg from 1813 to 1816. Here he 

 was under the influence of the Naturphi- 

 losophie. Later he, too, as I learn from 

 the historians of medicine, achieved his 

 scientific independence. He is called by 

 Haeser the founder of exact modern clin- 

 ical methods in Germany; and was the 

 center of a great school of medical workers, 

 to which Virchow also later belonged. He 

 was a clinical organizer rather than a pro- 

 ductive writer; but the influence of philo- 

 sophical interests upon his work appears 

 to have been decided. 



To pass to another field of scientific 

 work. Von Baer, the embryologist, was a 

 pupil of Bollinger in Wiirzburg. Boll- 

 inger was a prominent medical Naturphi- 

 losoph. It was he who seems to have first 

 set both Von Baer and Von Baer's con- 

 temporary and coworker Pander to work 

 upon embryological researches. Bollinger 

 himself, as Naturphilosoph, had been led 

 to work upon comparative anatomy. His 

 merit as the inspirer and teacher of Von 

 Baer is expressly recognized by Franz 



