[10] The word fan here is an ambiguous term which seems to contain two key meanings: becoming the opposite, and returning to its root or original point. Lao zi uses it to denote both, forming a dialectical interrelationship between the things involved. See our later discussion of the movement of the Dao, especially Chapter 40 (DDJ).
[11] It is proclaimed in the Yi Zhuan (Commentary on The Book of Changes) that there are three great things in the universe--including Heaven, earth and man. Yet there is one more great thing according to Lao Zi, that is, the Dao, which is considered to be the origin of all things.
[12] It is historically significant to rank man as one of the four great things in the universe. By so doing, man is placed in a position to make a proper use of the other three and even all things. As a matter of fact, the values of all other things would be reduced to nil if not for the existence of man.
[13] The earth is tranquil and selfless, serving as an inexhaustible source of life. Man lives on the earth, where he can get what he needs to keep himself alive providing he works in harmony with its underlying law. Therefore, Wang Bi believes that man can be secured and assured so long as he acts upon the law of the earth.
[14] The Heaven (i.e. the sky) is high, endless and boundless. It may do favors to all things below without asking for anything in return. The earth does the same, but this is only possible when it follows the way of Heaven.
[15] This statement means that Heaven can maintain its completeness and fulfill its accomplishments only if it bases itself on the law of the Dao.
[16] Some Lao Zi scholars misinterpret dao fa zi ran as "The Dao follows Nature." The Dao is essentially natural and originally the mother of Heaven and earth, as another name for nature. When observing the working and essence of the Dao as a whole throughout this book, we tend to conclude that zi ran signifies "spontaneity" or "naturalness" in the context concerned. We therefore have rendered it thus: "The Dao follows the way of spontaneity" (of the way of naturalness). The way of spontaneity refers to Dao itself in practice.
Commentary:
This chapter attempts to expound, first of all, the existence of the Dao, featuring independence, everlastingness, pre-existence, absoluteness, etc. It is, in short, the master producer of all things in the universe, and the ultimate law to be followed.
Secondly, it exposes some fundamental qualities of the Dao--soundlessness, formlessness, greatness and boundlessness... All these imply that the Dao embraces and affects all things, even though it is not directly observable or tangible.
Thirdly, it illustrates the dynamic character of the Dao and its law of movement. The dialectic between its becoming its opposite and returning to its original point is highly enlightening and instructive with regard to the development and transition of world affairs in general and social matters in particular. As for this aspect, a detailed formulation will be supplied later, when we come to Chapter 40.
Last but not least, it highlights the Dao as the way of spontaneity or naturalness, and as the ultimate law to be followed by Heaven, earth and man. The Dao can be regarded as the hidden measure or determinant of all things in the world.

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