404 FKAGMENTS OF SCIENCE. 



beliefs upheld ; namely, the desire to have them true. 

 jAnd those to whom I refer as having studied this 

 question, believing the evidence offered in favour of 



/" spontaneous generation " to be vitiated by error, 

 cannot accept it. They know full well that the chemist 



x 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 ac- 

 (juainted with the structural power of matter, as evi- 

 denced in the phenomena of crystallisation. 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 

 antecedent life.' ! . 



Comparing the theory of evolution with other 

 theories, I thus express myself: 'The basis of the doc- 

 trine of evolution consists, not in an experimental de- 

 monstration 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. 1 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 in- 

 finitesimal span of which is offered to the investigation 

 of man.' Among thinking people, in my opinion, this 

 last conception has a higher ethical value than that of 

 1 Quoted by Clifford, 'Nineteenth Century,' 3, p. 726. 



