 But the fall of the Han dynasty in 220 CE reveals a fundamental problem of correlative cosmology, namely, human beings are incapable of fully discerning the cosmic pattern, nor can they completely apply the cosmic pattern to human affairs. Even if they tried to mimic the cosmic rhythm in governing the human world, the human world is far too complicated for anyone to handle. In the following seven hundred years, Yijing scholars retreated from fathoming the cosmos. Instead, they turned their attention to ordering the human world and looked for its deep structure.