All the western management schools can be divided into three categories according to their different starting points.The first is the human `starting point theory which is driven by the conflict between the non-finite human nature and the finite management knowledge.The second is the organization starting point theory which is driven by the conflict between the mechanism and the teleology.The last is the starting point theory which is driven by the conflict between the apriorism and empiricism.All the three kinds of conflicts can be boiled down to human nature′s paradox.So a conclusion is reached that all the western management theories can form a unified understanding on the basis of human nature.