In the first chapter of my book MANLIFE, copyrighted in 1923, I said: “To me, the most important thing in the universe is man—because I am a man. And as it is within my power to guide myself through life, I believe it sensible to learn something about man and the laws that govern my own movements.
 “Furthermore, if I can give what information I am able to gather to others that they may be benefited thereby and utilize this information toward increased efficiency and more successful and happy lives then I feel that it is my duty to do so irrespective of all other considerations.
 Before an airliner that will fly can be built the designer of it must first understand the laws upon which flight is based and then conform to those laws.
 Any airman knows that if an aircraft is not built right it will not fly right. He knows that the better the materials put into it and the more attention given to the details of construction the better will be its performance in action. He also knows that the better care he gives to it the better it will fly and the longer it will be of service.
 Thousands of airmen have lost their lives during the past because they went aloft in badly constructed aircraft or because they did not understand their machines or were careless in handling them.
 But while thousands of airmen lost their lives by not knowing or not having taken proper care of their aircraft, quadrillions of human beings have lost their lives prematurely because they did not know their own bodies or how to take care of them.
 Of all things that man should understand and care for the most is man. But of all things the average man knows the least about and gives the least care and attention to is himself.
 The average man not only does not try to develop himself by the proper methods, but actually abuses himself to the breakdown point, and then blames everything but himself for the misfortune.
 If nature had not formulated very wise laws for man’s protection against himself, he would have long since become extinct, a victim of his own death dealing habits.
 If a man could have but one suit of clothes during his entire life, it is quite certain that he would treasure it above all things. and endeavor, by the most careful methods, to make it last as long as possible. He would study the art of making clothes and how the materials of which clothes are composed could be strengthened and preserved and he would learn how to combat to the best advantage the ravaging elements which cause the decay of those materials.
 A thousand times more should he study how man is made, how materials of which he is composed can be improved and how to overcome the dangerous elements which destroy him.
 Preserving and improving materials machines or human beings gives them longer life and increased efficiency and keeps them “younger” for a longer period.