200 HAECKEL 



imagination, when it is necessary to press on to 

 the great final conclusion, a new synthesis of the 

 defective positive data. What does Johannes 

 Miiller say ? " Imagination is an indispensable 

 servant ; it is by means of it we make the 

 combinations that lead to important discoveries. 

 The man of science needs, in harmonious co- 

 operation, the discriminating force of the analytic 

 intelligence and the generalising force of the 

 synthetic imagination. " That is spoken from 

 the depths of Haeckel's heart, and he drives it 

 home. 



Nothing is more amusing than to find Haeckel's 

 later opponents saying, apropos of any particular 

 question, that his statement springs from his 

 " imagination," as if it were something wholly un- 

 scientific that the naturalist must shun like the 

 pest ; or again, that Haeckel here or there falls a 

 victim to the deadly enemy of all scientific re- 

 search, natural philosophy. It is pointed out to 

 him as a great discovery which he must approach 

 in a proper penitential spirit to him who has 

 discussed these matters so unequivocally in his 

 first theoretical work. 



As a fact, these methodological chapters in the 

 first volume are as clear as crystal. The titles 

 will seem strange to the man who thinks he can 

 do without any philosophical instruction in zoology 

 and botany, and wants to hear only of cells, 

 tissues, stalks, leaves, bones, scales, and so on, 

 in a general morphology. One chapter has the 

 heading : " Empiricism and Philosophy (Experi- 



