638 Studies in the Tlieory of Descent. 



Thus, even without the foregoing special investi- 

 gations we should deny a phyletic vital force ; the 

 more so as its admission is fraught with the 

 greatest consequences, since it involves a re- 

 nunciation of the possibility of comprehending 

 the organic world. We should, on this assump- 

 tion, at once cut ourselves off from all possible 

 mechanical explanation of organic nature, *'. e. 

 from all explanation conformable to law. But 

 this signifies no less than the renunciation of all 

 further inquiry ; for what is investigation in natural 

 science but the attempt to indicate the mechanism 

 through which the phenomena of the world are 

 brought about ? Where this mechanism ceases 

 science is no longer possible, and transcendental 

 philosophy alone has a voice. 



This conception represents very precisely the 

 well-known decision of Kant: " Since we cannot 

 in any case know a priori to what extent the 

 mechanism of Nature serves as a means to every 

 final purpose in the latter, or how far the me- 

 chanical explanation possible to us reaches," 

 natural science must everywhere press the attempt 

 at mechanical explanation as far as possible. 

 This obligation of natural science will be conceded 

 even by those who lay great stress upon the ne- 

 cessity for assuming a designing principle. Thus, 

 Karl Ernst von Baer states that we have no right 

 " to assert of the individual processes of Nature, 

 even when these evidently lead to a definite result, 



