CHAPTEK XXIV 



ON SPECIES 



ILLUSTEATIONS of the way in which Hooker's own conceptions 

 of species and their problems took shape may be drawn from 

 his correspondence during this period. He viewed the question 

 from two sides, for he was the shining exception who gave 

 point to Darwin's complaint : 1 



How few generalises there are among systematists. 

 I really suspect there is something absolutely opposed to 

 each other and hostile in the two frames of mind required 

 for systematising and reasoning on a large collection of 

 facts. (C.D. ii. 39,) 



His mind was scientific in both the wider and the narrower 

 sense. It combined observation with generalisation, the need 

 for orderly detail with the equally impelling need for principles 

 to give these ordered details an intelligible interpretation. 



The primary object of science is order, and order is expressed 

 by classification. A perfect classification seeks its basis in 

 all the criteria gradually brought to light by research. Collec- 

 tion, labelling, grouping by external likeness is not enough. 

 Each advance in scientific order expresses more truly the 

 inner workings of nature, and to improve classification, there- 

 fore, is of more vital importance than to add to the store of ac- 

 cumulated material. Thus a group given individual importance 

 on inadequate grounds became an offence against science, and 

 obscured yet further the dark question of the origin of species. 

 To reason on the ill-defined was hopeless. And so ill-defined 



1 See further, vol. ii. pp. 18, 26-31 ; Essay on the Distribution of Arctic Plants 



465 



