The preceding lessons were written through a period of many years' active practise in treating dis-eases by scientific feeding. They were intended as a normal course to qualify doctors, nurses, and those who wished to treat dis-ease by this method. However, the demand for this class of information has come from people in every walk of life, therefore the lessons, and all technical matter composing this entire work have been most carefully revised and rewritten in simple language so that any person of ordinary intelligence can comprehend them. The following lesson is intended for the guidance of the practitioner in beginning his work in this branch of the healing art. Inasmuch as nearly all human ills are caused by errors in eating, the preceding lessons have been confined almost wholly to dis-eases that originate in the digestive organs. Lesson XVIII POINTS ON PRACTISE [Sidenote: Dietetic treatment is reconstructive] There are a great many abnormal conditions of the human body classed as dis-eases that bear a very remote relation to diet, but in practise the student will soon learn that many of these conditions, which have not been considered in these lessons, will entirely disappear when the diet is perfected. This is true because dietetic treatment, based upon the fundamental laws of nutrition, is reconstructive, hence every part of the anatomy shares in the general improvement. [Sidenote: Scope of scientific feeding] There are many logical arguments to support the theory that there are no incurable dis-eases. There are many cases, however, where the vitality has become so low that recovery from dis-ease is impossible, but if the patient could be taken in time, the correct diagnosis made, and the proper food, air, and exercise given, Nature would begin her work of rebuilding at once. In view of these facts it is somewhat difficult to fix a limit to the scope of scientific feeding. SUGGESTIONS FOR THE PRACTITIONER [Sidenote: The value of letters] The science of prescribing diet is a work that can be best conveyed to the patient in writing, hence one of the first and most important things for the new practitioner to do is to study the art of polemics--acquire the ability to write plain, convincing literature and letters. This is one of the greatest arts within the scope of human learning, and is probably susceptible of greater development than any other branch of human endeavor. Every person has his own individual method of expression that should be preserved and cultivated. Select some good author and copy his logic, but not his language. For this purpose I would recommend the works of Henry George, the great economic philosopher--and probably one of the greatest polementitians that ever lived. [Sidenote: Writing is mental calisthenics]