What Is Complexity?

The chapter provides definitions and characterizations of complexity, complexity science, complex adaptive systems, complexity thinking, and the complexity worldview. It is important to define these terms properly to avoid the loose “complexity talk” that has become fashionable in some of the business literature and popular press. In particular, the concept of complex adaptive systems is key to the rest of the book. Several definitions of complex adaptive systems are discussed, some of which overlap. Some background on the historical origins of complexity economics is also given. The chapter concludes with some philosophical considerations, particularly on philosophy of science and methodology, and introduces the concepts of complexity that are discussed in later chapters: nonlinearity, feedback, self-organization, emergence, evolution, history, and adaptation.