This book, written by two well-known scientists, represents an excellent ad dition to the Springer Series in Synergetics in several ways. It shows how by rather simple models we can gain remarkable insights into the behavior of complex systems. At the same time it demonstrates the progress made in this interdisciplinary field. While in the early days of Synergetics, the self organized coherent action of atoms in the laser - a physical device - was in the foreground of interest (cf. my book Synergetics: An Introduction (Springer, Berlin, Heidelberg, New York 1977)), the coherent action of nerve cells got into the focus of research, as is witnessed by the book by P. Tass in this series (P. Tass, Phase Resetting in Medicine and Biology (Springer, Berlin, Heidel berg, New York 1999)). In these books the elements were disturbed by noise. Now, in the present book by Mikhailov and Calenbuhr, the self-organized coherent action of otherwise chaotic elements is studied and important as well as surprising results by Kaneko, Mikhailov and others are presented. Let me mention just another highly interesting problem treated in this book: the coherent interaction of tens of thousands of reactions going on in biological cells. But other phenomena, such as the formation of swarms of fish or the collective behavior of ants, are also modelled. These are just a few examples of the many fascinating subjects dealt with in this book that relate to many disciplines under unifying aspects.