xyz THE HISTORY OF BIOLOGY 



hoped for universal peace in the future. The highest feeling he knew he used 

 to express in the following words: "The starry heavens above me, the sense 

 of duty within me." These words are actually carved on his gravestone. 



His influence 

 Through his critical philosophy Kant has played an important part in 

 human cultural development in general, and not least in scientific develop- 

 ment. Thanks to his criticism, biology was freed from the question, which 

 had so often arisen and yet had never been solved, of the relation between 

 soul and body; biological research had, as its exclusive mission, to explain 

 the material course of the phenomena of life, while the investigation of the 

 spiritual side of the soul-life became the function of the science of psy- 

 chology, employing entirely different methods. But in other respects, too, 

 Kant's critical philosophy exercised an influence upon the development of 

 biology in the century that followed; many of its leading biologists have 

 been keen supporters of Kant; for instance, Johannes Miiller, to mention only 

 one of the most eminent. But Kant's practical criticism of reason has also 

 indirectly affected the development of natural science. He thereby established 

 that reason can neither prove nor disprove man's personal ideas of faith and 

 conscience, so that any attempt to influence what the individual holds in 

 high esteem and deep reverence is both unjustifiable and irrational, whether 

 it is done in the name of the Church or in that of science. His principle, 

 just and reasonable though it is, has nevertheless found it difficult to gain 

 a hearing; ever since then, and indeed up to the present day, there have been 

 disputes between "faith and knowledge," brought about not least by the 

 fact that the ecclesiastical authorities claim that their doctrines shall be 

 accepted in their entirety as objectively true. The Roman Catholic Church 

 in particular has banned Kant and his philosophy. But even his contem- 

 poraries found it difficult to reconcile themselves to the strict self-control 

 that Kant enjoins upon human thought; that nothing was to be known of 

 "things in themselves" annoyed both the old philosophers of enlighten- 

 ment, who found Kant's thoughts difficult to grasp and oversubtle, and also 

 the champions of the mystical-romantic class, which strove after a uniform, 

 comprehensive view of existence. In particular, thinkers in the latter di- 

 rection, while adopting certain of Kant's principles, thought to bring human 

 knowledge beyond the contrast between personal consciousness and the 

 ''Ding an sich" ; as a matter of fact, the whole of the beginning of the nine- 

 teenth century was full of efforts of this kind, which have left their mark 

 on every science, and indeed on the whole of human culture during this 

 period of history. And so far as they influenced the development of biology, 

 they will be briefly touched upon in the following pages. 



JoHANN Gottfried Herder (1744-1803) was a fellow-countryman and 

 disciple of Kant's. He was ordained a minister and held a living for a time 



