FOREWORD IX 



Any acceleration in the process of aging in a senescent in- 

 dividual signifies the incidence of a disease, which should 

 be detected. It also becomes obvious that the value of a day 

 is much greater for a child than for his parents and his 

 teachers. The younger a child is, the richer his life in physio- 

 logical and psychical values. Such a fact should not be 

 neglected by educators. Every moment of the existence of a 

 child must be utilized for his formation. A clear realization 

 of the enormous value of physical time for children would 

 bring about a real progress in education and in the quality 

 of individuals. The knowledge of physiological time is 

 equivalent to the knowledge of life itself, because time can- 

 not be separated from life. The deeper this knowledge, the 

 more successful will be our approach to the mystery of our 

 self. For these reasons, I am happy to present this book by 

 Lecomte du Noiiy to the American public. 



Alexis Carrel 



Rockefeller Institute for Medical Research, 



New Yor^ 



