Everything is one thing until one thing is one thing. Then everything is everything. Or as Lao Tzu puts it:
The Tao is nameless.
What can be named is not eternal.
The nameless is the beginning of heaven and earth.
The name is the mother of the ten thousand things.
“The Heavens” separates the universe from our world then “sky” cleaves from “earth”. The definition “tree” divides it from the earth from which it springs. “Wood” kills the tree and “Plank” carves it up.
This is the intellectual path by which the thing we are part of becomes the things we can use.