*7S (6 4 ) 



law we ought, I think', to be cautious in limiting his 

 intellectual horizon. If there be the least doubt in the 

 matter, it ought to be given in favor of the freedom of 

 such a mind. To it a vast possibility is in itself a 

 dynamic power, though the possibility may never be 

 drawn upon. 



It gives me pleasure to think that the facts and 

 reasonings of this discourse tend rather towards the 

 justification of Mr. Darwin than towards his condemna- 

 tion, that they tend rather to augment than to diminish 

 the cubic space demanded by this soaring speculator ; 

 .for they seem to show the perfect competence of matter 

 and force, as regards divisibility and distribution, to bear 

 the heaviest strain that he has hitherto imposed upon 

 them. 



In the case of Mr. Darwin, observation, imagination, 

 and reason combined have run back with wonderful 

 sagacity and success over a certain length of the line of 

 biological succession. Guided by analogy, in his " Ori- 

 gin of Species " he placed as the root of life a primor- 

 dial germ, from which he conceived the amazing rich- 

 ness and variety of the life that now is upon the earth's 

 surface, might be deduced. If this were true it would, 

 not be final. The human imagination would infallibly 

 look behind the germ, and inquire into the history of its 

 genesis. 



Certainty is here hopeless, but the materials for an 

 opinion may be attainable. In this dim twilight of 

 speculation the inquirer welcomes every gleam, and seeks 

 to augment his light by indirect incidences. He studies 

 the methods of nature in the ages and the worlds within 

 his reach, in order to shape the course of imagination 

 In the antecedent ages and worlds. And though the 



