246 THE PRINCIPLES OF HEREDITY 



brighter, now darker, reaches it, and conveys no meaning. 

 Sounds, smells, the feelings of touch, and the joint or 

 muscular sensations from various parts of its body convey 

 no definite meanings. Pain causes the child to raise an 

 instinctive cry, unmeaning to itself, for help. If it knows 

 enough to wish to move its arms it is just as likely to move 

 its leg; if it seeks to touch its toe, it is just as likely to 

 touch its head. But in a few weeks it evolves order out of 

 chaos. Soon sight, hearing, touch, and other sensations 

 convey definite meanings. It moves its limbs in a definite 

 way. It comprehends to a wonderful degree the world 

 around it. No grown man could do the like. 



407. In a year or two the child learns to walk and speak 

 a language and a vast deal besides. The real intellectual 

 giants are the little children. Adults are dwarfs standing 

 on the shoulders of giants, on the shoulders of their former 

 selves. They make use of the knowledge, the data, the 

 reasoning powers they acquired as little children. The world 

 would be different and infinitely better if grown people in 

 addition to their stored knowledge could retain the child's 

 power of learning, of changing, of growing mentally in 

 response to fresh experience. There would, then, for ex- 

 ample, be only one religion left in the world the true 

 religion, whichever that may be. Men would not adhere 

 blindly to untruths which the progress of knowledge has 

 rendered obvious. They would never have been martyred 

 for saying that the world was round, nor trembled to declare 

 that it was more than six thousand years old. No Milton of 

 science, mute now and inglorious for ever, would have 

 preached to deaf and hostile ears. The material and 

 intellectual stagnation, the stupid insect-like incapacity to 

 learn, which the people of so many countries exhibit, and 

 which hamper even the most enlightened nations, would 

 fade like a dream. The wheels of progress would move 

 smooth and fast. There would be no poverty and no crime. 



408. The organ of man's mind, the physical concomitant 

 of his consciousness and intellect, is his brain. For a limited 

 time after birth his brain increases very rapidly in size ; but 

 the rate of growth diminishes gradually till it ceases when 

 adult life is reached. The brain is contained in a box con- 

 sisting of a number of bones, which in early life grow by 

 spreading at their edges, thus permitting the expansion of 

 the brain. Later the bones coalesce into one mass, and the 

 expansion of the brain is checked. The physical conditions 

 thus afford an explanation of the mental phenomena. The 



