With collective behaviors playing a fundamental role in many scientific and technical disciplines, the book, after an overview on the background to systemics, introduces the concept of Collective Being as a Multiple System established by processes of emergence and self-organization of the same agents simultaneously or dynamically interacting in different ways. The general principles underlying this approach are grounded on the theoretical role of the observer. This extended view allows to model in a more suitable way complex systems, such as in physics, biology and economics. The Dynamical Usage of Models (DYSAM) is the related modelling methodology. This innovating approach is applied to artificial and natural systems equipped with cognitive systems, such as autonomous robots and social systems. The authors discuss in two different chapters both traditional (i.e. based on dynamical systems and dissipative structures) and non-traditional (i.e. based on theory of phase transitions, Synergetics and connectionistic models) models of emergence. The book also introduces an innovative methodology for detecting the establishment of processes of emergence based on changes of ergodicity. After a theoretical introduction of the concepts, the authors discuss the application to social systems and cognitive systems. Two conclusive appendices on (1) Some systemic properties and (2) Some questions and answers about Systemics, help the reader to have a synthesized view of the book.