2S THE EVOLUTION THEORY 



(>r////H ('/■ N/rc/Vs. puMislifil ill I'ji^lisli in i (SyS, in German in i(S59 

 unli'ss wo i'iill\- rcali/r how conqilctcly tlio l)ioloo-ists of that time had 

 tunifil :i\v;iv iVoiu liciu'ial jiroltlems. I can only say that we, who 

 weiT I hell tilt' yoinin-or nicn, studying in tlie fifties, had no idea that 

 a theory of I'vohitidii had e\( r lieen })ut forward, for no one spoke 

 of it to us, and it was n('\ cr mentioned in a lecture. It seemed as 

 if all the teachers in our universities had drunk of the waters of 

 Lethe, and had utterly forgotten that such a theory had ever been 

 discussed, or as if they were asliamed of these philosophical flights on 

 the part of natural science, and wished to guard their students from 

 similar de\iations. The over-speculation of the ' Naturphilosophie ' 

 had left in their minds a deep antipathy to all far-reaching de- 

 ductions, and, in their legitimate striving after purely inductive 

 investigation, they forgot that the mere gathering of fa,cts is not 

 enough, that the drawing of conclusions is an essential part of the 

 induction, and that a mass of bare facts, however enormous, does not 

 constitute a science. 



One of ni}^ most stimulating teachers at that time, the gifted 

 anatomist, Jacob Henle, had written as a motto under his picture^ 

 ' Tliere is a virtue of renunciation, not in the province of morality 

 alone, but in that of intellect as well,' a sentence which exjaressly 

 indicated the desirability of refraining from all attempts to probe 

 into the more general problems of life. Thus the young students 

 of tliat time were nourished only on the results of detailed research, 

 in part indeed interesting enough, but in part dry and, because 

 uncorrelated, unintelligible in the higher sense, and only here and 

 there awakening a deeper interest, when', as in physiology and in 

 embryolog}^, they formed a connected system in themselves. Without 

 being fully clear as to what was lacking, we certainly missed the 

 deeper correlation of the many separate disciplines. 



It is therefore not to be wondered that Darwin's book fell like 

 a bolt from the blue ; it was eagerly devoured, and while it excited 

 in the minds of the younger students delight and enthusiasm, it 

 aroused among the older naturalists anything from cool aversion 

 to violent opposition. The w-orld was as though thunderstruck, as 

 we can readily see from the preface with which the excellent zoologist 

 of Heidelberg, Bronn, introduced his translation of Darwin's book, 

 Avhere he asks this question among others, ' How will it be with you, 

 dear reader, after you have read this book ? ' and so forth. 



But before I enter on a detailed examination of the contents of 

 this epoch-making book, I should like to say a few words about the 

 man himself, who thus revolutionized our thinking. 



