282 THE WEENOE AND THE WHITHER OF MAN 



could invent traps and weapons against which muscle 

 was of little avail. Just at present brain is of use to, 

 and valued by, a large portion of society in propor- 

 tion to its efficiency in making and selfishly spending 

 money. But slowly and surely it is becoming of use 

 as an organ of thought, for the sake of the truth which 

 it can discover and incarnate. 



Natural selection works thus apparently for the sur- 

 vival of the individuals possessing in the aggregate the 

 most complete conformity to environment. Let us 

 now imagine that an animal is so constructed as to be 

 capable of variation along several disadvantageous 

 or neutral lines, and along only one which is advan- 

 tageous. The development would of com'se proceed 

 along the advantageous line. Let us farther imagine 

 that to the descendants of this individual two, and 

 only two, advantageous lines of variations are allowed 

 by its structure. Then natural selection would prob- 

 ably favor the decidedly advantageous line, if such 

 there were. But as long as the structure of the ani- 

 mal allows variation along only a few lines, the two 

 advantageous variations would, according to the law 

 of probabilities, frequently occur in the same individ- 

 ual. The eggs and spermatozoa of two such individ- 

 uals might not infrequently unite, and thus in time 

 the two characteristics be inherited by a large fraction 

 of the species. 



And now let me quote from Mr. Spencer : 



" But in proportion as the life grows complex — in proportion 

 as a healthy existence cannot be secured by a large endowment 

 of some one power, but demands many powers ; in the same 

 proportion do there arise obstacles to the increase of any par- 

 ticular power, by 'the preservation of favored races in the 



