Physical and social worlds are full of change, paradox and contradiction. There are no simple, unchanging stable states or states to which there is equilibrium-establishing movement. The "normal" state is not one of balance and equilibrium. Any system is "complex". Policies never straightforwardly restore equilibrium. The equilibrium models dominant in most economic system analyses, especially general equilibrium models, can be critiqued since they ignore the huge array of positive feedbacks. Thus, systems should be viewed as dynamic and processual, demonstrating the power of the second law of thermodynamics, in which physical and social systems are seen as moving towards entropy. Systems can be broadly viewed as unpredictable, open rather than closed, with energy and matter flowing in and out. Systems are characterised by a lack of proportionality or "non-linearity" between the apparent "causes" and "effects" of events and processes. Various implications for thinking futures are examined in the light of this complex systems thinking.
Key words: Complexity systems, futures, mobility, crisis