We have seen that as mankind rises in the scale of civilization the body becomes increasingly less important. Nevertheless, I wish it to be clearly understood, that I do not maintain that it is preferable to be ill than well, but only that each state has its own peculiar privileges, which are rarely interchangeable. Health and sickness are merely different roads to achievement. The earth requires rain as well as sunshine; we need both tears and laughter; navvies are necessary and so are philosophers. The book details how people from many professions who had some or other physical disability or pain reached their goals. The introduction is by Kate Douglas Wiggin.