Organizations of all kinds struggle to understand, adapt, respond and manipulate changing conditions in their internal and external environments. Approaches based on the causal, linear logic of mechanistic sciences and engineering continue to play an important role, given people's ability to create order. But such approaches are valid only within carefully circumscribed boundaries. They become counterproductive when the same organizations display the highly reflexive, context-dependent, dynamic nature of systems in which agents learn and adapt and new patterns emerge. The rapidly expanding discussion about complex systems offers important contributions to the integration of diverse perspectives and ultimately new insights into organizational effectiveness. There is increasing interest in complexity in mainstream business education, as well as in specialist business disciplines such as knowledge management. Real world systems can't be completely designed, controlled, understood or predicted, even by the so-called sciences of complexity, but they can be more effective when understood as complex systems. While many scientific disciplines explore complexity principally through abstract mathematical models and simulations, Emergence: Complexity & Organization explores the emerging understanding of human systems from both the 'hard' quantitative sciences and the 'soft' qualitative perspectives. This 2009 Annual includes articles from Anet Potgieter, Benyamin Lichtenstein, Kate Crawford, Donald Gilstrap, Liz Varga, Steven Wallis, and many more, that explore a range of complexity-related topics from philosophical concerns through to the practical application of complexity ideas, concepts and frameworks in human organizations. Also included are a series of four reproductions of classical papers in the fields of complexity and systems, each with critical introductions that explore their modern relevance: "Thoughts on Organization Theory" by Anatol Rapoport & William J. Horvath (originally published in 1959) "The Doctrine of Levels" by George P. Conger (originally published in 1925) "The Role of Somatic Change in Evolution" by Gregory Bateson (originally published in 1963) "The Status of Emergence" by Paul Henle (originally published in 1942)