648 FRAGMENTS OF SCIENCE, 



it falls in with our belief, we should eagerly close with the 

 evidence referred to. But there is in the true man of 

 science a desire stronger than the wish to have his beliefs 

 upheld; namely, the desire to have them true. And those 

 to whom I refer as having studied this question, believing 

 the evidence offered in favor of ' spontaneous generation ' 

 to be vitiated by error, cannot accept it. They know full 

 well that the chemist now prepares from inorganic matter 

 a vast array of substances, which were some time ago 

 regarded as the products solely of vitality. They are 

 intimately acquainted with the structural power of 

 matter, as evidenced in the phenomena of crystallization. 

 They can justify scientifically their belief in its potency, 

 under the proper conditions, to produce organisms. But, 

 in reply to your question, they will frankly admit their 

 inability to point to any satisfactory experimental proof 

 that life can be developed, save from demonstrable antece- 

 dent life." * 



Comparing the theory of evolution with other theories, 

 I thus express myself : " The basis of the doctrine of 

 evolution consists, not in an experimental demonstration 

 for the subject is hardly accessible to this mode of proof 

 but in its general harmony with scientific thought. From 

 contrast, moreover, it derives enormous relative strength. 

 On the one side we have a theory, which converts the 

 Power whose garment is seen in the visible universe into 

 an Artificer, fashioned after the human model, and acting 

 by broken efforts, as man is seen to act. On the other side 

 we have the conception that all we see around us and feel 

 within us the phenomena of physical nature as well as 

 those of the human mind have their unsearchable roots 

 in a cosmical life, if I dare apply the term, an infinitesimal 

 span of which is offered to the investigation of man." 

 Among thinking people, in my opinion, this last concep- 

 tion has a higher ethical value than that of a personal 

 artificer. Be that as it may, I make here no claim for the 

 theory of evolution which can reasonably be refused. 



" Ten years have elapsed," said Dr. Hooker at Norwich 

 in 1868, f "since the publication of 'The Origin of 

 Species by Natural Selection/ and it is therefore not too 



* Quoted by Clifford, Nineteenth Century, 3, p. 726. 

 \ President's Address to the British Association. 



