2OO Heredity and Social Progress 



The first of these differentiations is that of 

 mind and body. Between the two there is no 

 sharp demarcation. The one is merely more 

 mind than body, and the other is more body 

 than mind. A second differentiation is be- 

 tween the sensory and motor organs. Here 

 again we find highly differentiated functions 

 but no sharp limits ; the sensory organs have 

 some motor functions and the motor organs 

 contain elements that would, under favor- 

 able conditions, transmit afferent impulses. A 

 third differentiation results in acquired and 

 natural characters. Natural characters have 

 inherited organic connections by which each 

 action or function follows directly after its 

 organic antecedent. Acquired characters are 

 linked in consciousness. The two elements 

 thus united had their organic beginnings at 

 different stages of evolution, and thus are in 

 their evolution independent. The conscious 

 element needed to unite them is a mental 

 association. 



Another differentiation is between organs of 

 action and organs of control. The conscious, 

 the sensory, the acquired, dominate the organs of 



