The chapter opens with a list in a formula that reads like something quoted rather than composed. Of old, these attained the one: heaven attained it and became clear, earth attained it and became settled, spirits attained it and became numinous, valleys attained it and became full, the ten thousand things attained it and lived, lords and kings attained it and became the standard of the world.
Six items, in descending order from heaven to human government, each with the same verb and each with a different result. The one is not defined anywhere in the chapter. It appears again in chapter twenty-two, where the sage holds to it, and in chapter forty-two as the first thing the way gives birth to, and in all three places it functions as whatever makes a thing be what it is rather than a heap.
The second half runs the list backwards as a set of threats. Without what makes it clear, heaven might crack. Without what settles it, earth might quake. The reversal is what turns an inventory into an argument, because it says that the qualities named are not properties the items own but conditions they hold on loan.
The chapter is one of the places where the book's vocabulary is closest to the religious and cosmological language of its period. Spirits becoming numinous is not a metaphor about human character, and valleys filling is not obviously about humility. This is a passage that assumes an ordered cosmos of heaven, earth, spirits and rulers, and it locates the way underneath all four rather than beside them.