So THE HISTOPtY OF CEEATION. 



their hard-won knowledge of details lies in the general 

 results which more comprehensive minds will one day 

 derive from them. 



From a general survey of the com^se of biological develop- 

 ment since Linngeus' time, we can easily see, as Bar has 

 pointed out, a continual vacillation between these two ten- 

 dencies, at one time a prevalence of the empirical — the 

 so-called exact — and then again of the philosophical or 

 speculative tendency. Thus at the end of the last century, 

 in opposition to Linnaeus' purely empirical school, a natural- 

 philosophical reaction took place, the moving spirits of 

 which, Lamarck, Geoffroy St. Hilaire, Goethe, and Oken, 

 endeavoured by their mental work to introduce light and 

 order into the chaos of the accumulated empirical raw 

 material. In opposition to the many errors and specu- 

 lations of these natural philosophers, who went too far, 

 Cuvier then came forward, introducing a second, purely 

 empirical period. It reached its most one-sided development 

 between the years 1830-1860, and there now followed a 

 second philosophical reaction, caused by Darwin's work. 

 Thus during the last ten years, men again have begun to 

 endeavour to obtain a knowledge of the general laws of 

 natiu'e, to which, after all, all detailed knowledge of experi- 

 ence serves only as a foundation, and through which alone 

 it acquires its true value. It is through philosophy alone 

 that natural knowledge becomes a true science, that is, 

 a philosophy of nature. (Gen. Morph. i. 63-108.) 



Jean Lamarck and Wolfgang Goethe stand at the head of 

 all the gTeat philosophers of nature who first established a 

 theory of organic development, and who are the illustrious 

 fellow-workers of Darwin. I turn first to our beloved 



