A good wanderer leaves no trace.
A good speaker does not stutter.
A good counter needs no calculator.
A good door needs no lock,
Still it can't be opened.
A good mooring needs no knot,
Still no one can untie it.

Therefore the sage takes care of all people,
Forsaking no one.
He takes care of all things,
Forsaking nothing.
This is called following the light.

So, a good person is the bad person's teacher.
A bad person is the good person's task.
The one who does not honor the teacher
And the one who does not honor the task,
Although ever so knowledgeable,
They are confused.
This is called the subtle essence

∆ Tao Te Ching | Chapter 27