The subject of diet is one of the foremost topics of the present day in public interest. Newspapers and magazines teem with articles on the subject. The counters of the bookshops are filled with volumes unfolding the mysteries of proteins, starches, vitamins, and so forth. dust now the whole world is food-conscious. Experts on the subject are saying that physically you become the thing that you eat — that your whole body is really composed of the food that you have eaten in the past. What you eat today, they say, will be in your bloodstream after the lapse of so many hours, and it is your blood-stream that builds all the tissues composing your body — and there you are. Of course, no sensible person has any quarrel with all this. It is perfectly true, as far as it goes, and the only surprising thing is that it has taken the world so long to find it out; but in this article I am going to deal with the subject of dieting at a level that is infinitely more profound and far-reaching in its effects. I refer of course to mental dieting.