294 ■ CONCLUSION. : [Chap. XV. 



1 

 the belief in the revolution of the earth on its own axis 



was until lately supported by hardly any direct evidence. 

 It is no valid objection that science as yet throws no 

 light on the far higher problem of the essence or origin 

 of life. Who can explain what is the essence of the 

 attraction of gravity? No one now objects to following 

 out the results consequent on this unknown element 

 of attraction; nowithstanding that Leibnitz formerly ac- 

 cused Newton of introducing " occult qualities and 

 miracles into philosophy." 



I see no good reason why the views given in this vol- 

 ume should shock the religious feelings of any one. It 

 is satisfactory, as showing how transient such impres- 

 sions are, to remember that the greatest discovery ever 

 made by man, namely, the law of the attraction of grav- 

 ity, was also attacked by Leibnitz, " as subversive of 

 natural, and inferentially of revealed, religion." A cele- 

 brated author and divine has written to me that " he has 

 " gradually learnt to see that it is just as noble a concep- 

 " tion of the Deity to believe that He created a few ori- 

 " ginal forms capable of self-development into other and 

 " needful forms, as to believe that He required a fresh act 

 " of creation to supply the voids caused by the action of 

 " His laws." 



Why, it may be asked, until recently did nearly all 

 the most eminent living naturalists and geologists dis- 

 believe in the mutability of species. It cannot be as- 

 serted that organic beings in a state of nature are sub- 

 ject to no variation; it cannot be proved that the 

 amount of variation in the course of long ages is a lim- 

 ited quantity; no clear distinction has been, or can be, 

 drawn between species and well-marked varieties. It 

 cannot be maintained that species when intercrossed are 



