Book excerpt: This book shows how health can be maintained and improved by fulfilling the basic physical and mental needs in proper proportion. Internal insanitation is the basic cause of all diseases, ranging from the common cold to the dreaded cancer. Disease is, in reality, a diminution in the health level, and cure lies in the restoration of health, and in the removal of the cause of disease. The science of nature cure charts the sane, safe and hygienic way of regaining health.