摘要：This paper critically examines the idea that planning theory experiences major theoretical shifts. Through a consideration of contributions from several academics, it is shown that different theoretical standpoints in planning persist and coexist. A model is proposed to aid understanding of this situation: the Hydra Model. This model views planning as a discipline in which several standpoints maintain a competitive interaction. This is positive: it is the best way to promote lively dialogue and to develop new understandings. However it is considered negative for planners to adopt a single standpoint. Theories are presented as tools for good practice, not as something to which planners should commit. In aiming for the emergence of this type of planner — an individual capable of flowing from one theory to another according to a discretionary view of particular situations — some suggestions for planning education are presented.
