to the Fourth German Edition Rational Phytotherapy continues to add a truly significant dimen sion to the practice of evidence-based herbal medicine. Prepara tion of a new edition, so short a time after publication of the pre vious English version, was necessitated by the rapid increase in the number of scientific and clinical studies attesting to the safe ty and utility of phytomedicines. The results of these recent inves tigations are now incorporated in the revised text of this volume. Comprehensive, updated information on scientific studies and clinical trials of the therapeutically useful botanical drugs is now placed before interested readers worldwide. Even the most CurS01Y acquaintance with phytotherapy, herbal treatment, botanical medicine - whatever you choose to call i- causes one to recognize that throughout most of the world, and especially in the United States and the United Kingdom, the prac tice is at best still an imperfect art. In Germany, the use of plant drugs is a science. There are many reasons for this. Tradition can certainly not be discounted. However, the principal reason is, without question, the enlightened system of laws and regulations governing the sale and use of such products in that country. Basically, the regulations in Germany permit phytomedicines to be sold either as self-selected or prescription drugs provided there is absolute proof of their safety and reasonable certainty of their efficacy. The words "reasonable certainty" are extremely They require that some scientific and clinical evi important here.