All the time that I write these chapters about health I feel guilty. I know that the wholesome food I recommend costs money, and I know that surgery and dentistry cost money--yes, even sunlight and fresh air and recreation; even a fast, because you have to rest while you take it, and you have to have a roof over your head, and warmth in winter time, and somebody to wait upon you when you are weak. I know that for a great many of the people who read what I write, all these things are impossible of attainment; I know that for the great majority of the common people the benefits of science do not exist. Science discovers how to prevent disease, but the discoveries are not applied, because the profit system controls the world, and the profit system wants the labor of the poor, regardless of what happens to their health. If the people fall ill, they are thrown upon the scrap heap, and the profit system finds others to take their place. Take, for example, tuberculosis. Tuberculosis is a germ infection, but it practically never gets hold upon a human body except when the body is reduced by undernourishment and lack of fresh air. Tuberculosis, therefore, is a disease of slums and jails. It is definitely and indisputably a disease of poverty. It could be wiped off the face of the earth in a single generation; and the same is true of typhus and typhoid. There is another whole host of ailments which could be wiped out by measures of public hygiene, plus education. This includes all the infant diseases, and the deadly venereal diseases. But the profit system stands in the way; and so, in these closing paragraphs of this Book of the Body, I say that there is one disease which is the deadliest of all, and the source of all others, and that disease is poverty. I know a certain physician to the rich, who is an honest and conscientious man. He said, "I loath my work. I am wasting my time. I am called in by these fat, over-fed rich people in their leisure class hotels, and what am I to say to them? Shall I say to them, 'You are living an abnormal life, and you can never be well until you cut out root and branch all your habits of self indulgence which are destroying you?' But no, I can't say that--not one time in a thousand. I am expected to be polite and serious, and to listen to them while they tell the long tiresome story of their symptoms, and I have to encourage them, and give them some temporary device that will remove some of the symptoms of their trouble."