Complexity is the unifying theory of biological and physical phenomena. It holds that at the root of all complex systems lie a few simple rules, taking the notion of chaos (which states that within seemingly chaotic systems are elements of order) a step further by actually identifying these rules. The author sees it as the dominant scientific trend of the 1990s, as scientists from many disciplines come together and begin to discover the underlying similarities in their fields.;Intended as an introduction to the theory of complexity, this book reports on conversations held with those at the forefront of developing the theory. There are no formulas, but sophisticated mathematical ideas are presented in the actual words of the scientists who work with them, applying complexity theory to the disciplines of physics, chemistry, biology, psychology, economics, linguistics, anthropology and computer science. The author's previous book, "Bones of Contention", won the Science Book Prize.