SCIENTIFIC USE OF THE IMAGINATION. 127 



overstepping the bounds of reason, that he is unwittingly 

 sinning against observed fact or demonstrated law for 

 a mind like that of Darwin can never sin wittingly 

 against either fact or 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 favour of the freedom of such a mind. To it a vast 

 possibility is in itself a dynamic power, though the pos- 

 sibility may never be drawn upon. It gives me plea- 

 sure to think that the facts and reasonings of this 

 discourse tend rather towards the justification of Mr. 

 Darwin, than towards his condemnation ; 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. Gruided by analogy, in his 

 ' Origin of Species ' he placed at the root of life a 

 primordial germ, from which he conceived the amazing 

 variety of the organisms now upon the earth's surface 

 might be deduced. If this hypothesis were even true, 

 it would not be final. The human mind would in- 

 fallibly look behind the germ, tnd however hopeless the 

 attempt, would enquire into the history of its genesis. 

 In this dim twilight of conjecture the searcher 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 speculation in antecedent ages and 

 worlds. And though the certainty possessed by experi- 

 mental enquiry is here shut out, we are not left entirely 

 without guidance. From the examination of the solar 

 system, Kant and Laplace came to the conclusion that its 



