"The vertebral theory of the skull ," Mechnikov said, 



was inherited by science from Naturphilosophie, that 

 strange mongrel that resulted from the union of 

 metaphysics with positive knowledge, and which, in 

 general, had significantly slowed the progress of 

 natural science. A whole generation of first-class 

 scientists was needed to purge the science of living 

 creatures of Naturphilosophie rubbish and to establish 

 a stable basis of that science. Regardless of the 

 antagonism between scientists and Naturphilosophie 

 scientists, the former took some theories gotten from 

 the latter, among which the vertebral theory of the 

 skull played an important role. Already you see that 

 it represents nothing significant in the line of 

 thought of the Naturphilosophie school. It is sufficient 

 to name one of the authors of the vertebral theory to 

 show whether one should believe its generalizations. 



Mechnikov mentions Goethe and then Ok en, and tells about the 

 circumstances of the establishment of this theory. After 

 that he gives embryological data about the sequence of 

 appearance of embryonic skull parts in vertebrates; these 

 data are incompatible with the vertebral theory. 



Mechnikov ! s statement on Naturphilosophie is excessively 

 strict. Engels, reflecting on the history of science, has 

 written the following concerning German Naturphilosophie: 



In it there were many absurd and imaginary things, but 

 not more than in the contemporary non-philosophical 

 theories of the empiricists. It included many intel- 

 ligent ideas which were beginning to be understood 

 when the theory of evolution started to spread. Thus, 

 Haeckel accurately recognized the services of 

 Treviranus and Oken. In his conception of the primary 

 mucus and the infusoria, Oken suggests as a postulate 

 of biology what was later actually discovered in the 

 protoplasm and cell.-* 



5. Engels, ANTI-DUHRING . Gospolitizdat, 1953, p. 11. 



146 



