This book presents the theory of anticipation, and establishes anticipation of the future as a legitimate topic of research. It examines anticipatory behavior, i.e. a behavior that ‘uses’ the future in its actual decisional process. The book shows that anticipation violates neither the ontological order of time nor causation. It explores the question of how different kinds of systems anticipate, and examines the risks and uses of such anticipatory practices. The book first summarizes the research on anticipation conducted within a range of different disciplines, and describes the connection between the anticipatory point of view and futures studies. Following that, its chapters on Wholes, Time and Emergence, make explicit the ontological framework within which anticipation finds its place. It then goes on to discuss Systems, Complexity, and the Modeling Relation, and provides the scientific background supporting anticipation. It restricts formal technicalities to one chapter, and presents those technicalities twice, in formal and plain words to advance understanding. The final chapter shows that all the threads presented in the previous chapters naturally converge toward what has come to be called “Discipline of Anticipation”