THE EVOLUTION IDEA 151 



selection in the production of certain external 

 colors. 



Kant's comprehensive view of cosmic Evolu- 

 tion and his hesitation as to the problem of causa- 

 tion are summed up in the following remarkable 

 passage (1790) , quoted by Haeckel:^ 



It is desirable to examine the great domain of 

 organized beings by means of a methodical compara- 

 tive anatomy, in order to discover whether we may 

 not find in them something resembling a system, 

 and that too in connection with their mode of gen- 

 eration, so that we may not be compelled to stop 

 short with a mere consideration of forms as they are 

 — which gives us no insight into their generation — 

 and need not despair of gaining a full insight into 

 this department of Nature. The agreement of so 

 many kinds of animals in a certain common plan of 

 structure, which seems to be visible not only in their 

 skeletons, but also in the arrangement of the other 

 parts — so that a wonderfully simple typical form, 

 by the shortening and lengthening of some parts, 

 and by the suppression and development of others, 

 might be able to produce an immense variety of 

 species — gives us a ray of hope, though feeble, that 

 here perhaps some result may be obtained, by the 

 application of the principle of the mechanism of 

 nature, without which, in fact, no science can exist. 

 This analogy of forms (in so far as they seem to 

 have been produced in accordance with a common 

 prototype, notwithstanding their great variety) 



'^Loc. cit., pp. 106-7. 



