GENERAL CONSIDERATION. 331 



any direction to suit these purposes. But when it 

 reaches high specialization in any one direction, it 

 loses its power to develop further. The graver's 

 tool can cut only one kind of line, and does this so 

 well that further advance is impossible. And so in 

 the organic world. An unspecialized animal is capa- 

 ble of great development in various directions, but 

 after it has become specialized its advance soon be- 

 comes limited and practically ceases. A tree cannot 

 grow forever. After reaching a certain size it ceases 

 to develop further growth, producing only leaves 

 and twigs. Now, it follows from this principle that 

 evolution is limited, and applying the principle to 

 man it will become probable, not only that he is the 

 highest animal which has appeared, but also the 

 highest that will appear. The last generalized fea- 

 ture which becomes developed is the mental power. 

 So far as we can see, this is the highest power; 

 including in the term mental, the moral powers 

 as well as the intellectual. The mental nature was 

 at one time an undeveloped feature, but it has now 

 become developed, and the specialization of this 

 last and highest quality has produced man. Now 

 this mental nature may go on developing and be- 

 coming more specialized. This we see is constantly 

 taking place. But the result can never be any thing 

 but man, since the distinctive characteristic of man 

 is the possession of highly developed mental powers. 

 Man stands at the top of the animal kingdom, not 

 because he has a more highly developed body than 

 other animals, for this is only partly true. It is be- 

 cause his distinctive characteristic is the great develop- 



