This growth principle applies to any aggregation 

 of units held together by more or less equitable give 

 and take, and common interests. If cooperative action 

 is increased through mutual adjustment and mutual 

 benefit, it binds the group more firmly together into 

 more stable, organic unity. If it decreases, resulting 

 in mutual disadvantage, the group inevitably breaks up 

 into smaller groups, or partnership in it is wholly dis- 

 solved. 



In the man-dog, or man-wheat, combination, and 

 in many others of like nature, the conditions are very 

 different. Here the components have interests in com- 

 mon. The union, although not organic or physical, is 

 nevertheless highly constructive, or creative. Each 

 constituent, in proportion to its own development, 

 serves the other so much the 'more, and creates new 

 powers in it. Thus the product of the union grows, 

 and tends to acquire larger powers for world service, 

 which could not have been acquired separately. 



In the man-dog combination, for example, the dog 

 is given a share of the greater security and larger free- 

 dom acquired by his human partner, and new powers 

 are created in the dog through his association with, 

 and his service to, man. On the other hand, man re- 

 ceives additional security, stability, and freedom of 

 action, through the peculiar physical and sensory pow- 

 ers, the affection and the intelligence of the dog; and 

 new and broader mental powers are created in man 

 through his service, sympathy, and affection for his 

 faithful comrade. 



The cooperative union of these two lives, therefore, 

 creates a growing power for world service. The po- 



