PLAY AND INSTINCT. 45 



usurpation by the intellectual powers of a realm where 

 they have not undisputed sway, explain the unfruitful- 

 ness of so many thinkers for the advancement of science. 

 It is difficult to say whether mere sentiment, which 

 assumes no definite form, or much reasoning tending to 

 no purport, has interfered more with our progress in 

 knowledge." But who has written this masterly indict- 

 ment of modern science? I fancy that one would not 

 easily detect the author did not certain artistic expres- 

 sions betray him, and withal the perfect style which is as 

 brilliant and as penetrating as a good sword.* 



Lamarck published his theory of development in 

 1801, and extended it in the Philosophie zoologique, 

 which appeared in 1809, as well as in the introduction 

 to his work on the Histoire naturelle des animaux sans 

 vertebres. As the fundamental principle of his theory, 

 he lays down the inheritance of acquired characters by 

 individuals (especially functional adaptations). Dar- 

 win included this principle in his theory advanced in 

 1859, but perfected it by his more important and com- 

 prehensive conception of natural selection. According 

 to it, not only functional adaptations, but also the in- 

 heritance of congenital characters produce changes in 

 species, so that in each generation congenital "indi- 

 vidual variations " appear of which the " fittest " always 

 come out best in the struggle for existence, and are 

 thus transmitted further (Spencer, Survival of the Fit- 

 test). In the whole organic world this principle rules, 

 adapting means to ends without there being any end — 

 that is, any conscious or voluntary end. The transcen- 

 dental-teleological principle is thus excluded. " The 



* Schiller, Ueber die Ssthetische Erziehung des Menschen, thir- 

 teenth letter. 



