The formulation discussed in this Chapter is a general principle that can be applied to any discussions on the relationship between appearances and reality. We devise a model to express this principle systematically. As an introduction to this model, we shall discuss the core principle of Tao philosophy and a systematic model to show the logic of Tao philosophy. The core principle may be deduced in its simplest form from Chapter 1 of the Tao Te Ching. 
This model is heuristic model, but should be vigorous enough for our purpose. After we analyze the Tao Te Ching, we conclude that Lao-tzu as a normal philosopher and his philosophy as an authentic philosophy of nature. We may take Tao to be the proper order of nature and this order may be seen among the things in the nature. It is clear that Lao-tzu should be treated as an authentic ancient philosopher, on the same footing as early Greek philosophers and Nagarjuna.
We can derive this model from the first Chapter of the Tao Te Ching.
 As “Occam’s razor” states, we should not compound explanation beyond what is required; the simplest theory is best.