In another place Engels talked about Oken as the first in 

 Germany to acknowledge the theory of development .6 Such a 

 general evaluation of Naturphilosophie was given by Engels 

 in "Ludwig Feuerbach": 



. . . with the help of data obtained by the most 



empiricistic natural science, it is possible to give 



fairly systematically a general picture of nature as 



a complete unity. To give such a general picture of 



nature was previously the task of what is called 



Naturphilosophie, which could only fill the gap with 



imaginary connections of the yet unknown actual group 



of phenomena. It substituted ideas for unavailable 



facts, replenishing the actual gaps only by imagination, 



In this case many clever thoughts emerged and many 



of the latest discoveries were foreseen, but also 



a lot was said which was nonsense. Otherwise it could 



7 

 not have existed at that time . 



Noting, therefore, the historical importance of Natur- 

 philosophie at the beginning of the nineteenth century, 

 Engels warned against useless attempts to raise it again in 

 contemporary natural science. Such an attempt, Engels wrote, 

 "is not only unnecessary, but also could be a step backward." 8 



Giving great significance to solving biological problems 

 of embryonic development, Oken turned to the independent 

 study of the embryology of vertebrate animals and made a 

 number of important factual discoveries. Their significance 

 was depreciated by Meckel's translation of K. F. Wolff's 

 work, "On the Formation of the Intestines, "^ where it was 

 revealed that Wolff had achieved Oken's most important data 

 forty years before in his paper in the "New Commentaries of 

 the Petersburg Academy of Science," which was completely 

 unknown to Oken. 



6. See Engels, DYNAMICS OF NATURE. Gospolitizdat, 1952, 

 p. 161. 



7. Engels, "Ludwig Feuerbach and the End of Classical German 

 Philosophy," K. Marx and F. Engels, WORKS, Vol. II. 

 Gospolitizdat, 1952, p. 370. 



8. Ibid . 



9. See Chapter 5. 



147 



