This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The Daodejing opens with a warning about itself: the Dao that can be spoken is not the constant Dao, the name that can be named is not the constant name. A reader expecting a system that will define its own central term is told, in the very first line, that the term resists definition, that language, built for naming discrete things, is the wrong tool for pointing at the pattern behind all things. This is not evasion. It is the argument.
What the text offers instead of definition is a set of images and reversals meant to loosen a reader's grip on fixed categories rather than replace them with new fixed categories. Water is praised because it yields to whatever it meets and yet wears down stone over time; the valley is praised over the mountain peak because it receives rather than dominates; the newborn infant is praised because it is soft and without rigid, defended positions, and softness, in the text's recurring argument, outlasts hardness the way water outlasts rock. The ruler who governs best, in the same logic, is barely known to exist to the people he governs, because he has not imposed himself on them; wu wei, non-action or effortless action aligned with the grain of things rather than against it, is the practical form this same insight takes when applied to conduct and governance rather than to metaphysics.
Zhuangzi, writing later, pushed the same instinct further and more playfully, using parables, a butterfly dream that leaves the dreamer unsure whether he is a man who dreamed he was a butterfly or a butterfly now dreaming he is a man, a cook whose knife never dulls because he cuts along the natural seams of the ox rather than forcing it through bone, to make the same case Laozi makes more solemnly: that the distinctions people treat as fixed and obvious, self and other, useful and useless, right and wrong, look a great deal less fixed once examined from more than one angle, and that wisdom lies less in choosing the correct side of each distinction than in holding all of them more lightly.