Tao Te Ching — Chapter 71

To know that you do not know is best. To not know, yet think you know — this is the disease. Only by recognizing this disease as a disease can you be free of it. The sage is free of it because he recognizes the disease as a disease — and so is not diseased.

James Legge (1891)

To know and yet (think) we do not know is the highest (attainment); not to know (and yet think) we do know is a disease. It is simply by being pained at (the thought of) having this disease that we are preserved from it. The sage has not the disease. He knows the pain that would be inseparable from it, and therefore he does not have it.

Dwight Goddard (1919)

To recognize one's ignorance of unknowable things is mental health, and to be ignorant of knowable things is sickness. Only by grieving over ignorance of knowable things are we in mental health. The wise man is wise because he understands his ignorance and is grieved over it.

This is one of the most compressed chapters in the book, turning on the repeated graph bing, "sickness" or "defect." The opening line is a near-cousin of Socrates' famous formula: zhi bu zhi shang — to know that one does not know is the highest. The complementary failing is bu zhi zhi — not to know, yet to take oneself as knowing. That false confidence Lao Tzu names a bing, a disease of the mind. The chapter is not against knowledge; it is against the particular sickness of unexamined certainty, the self-assurance that has never tested its own ground.

The cure is given in a deliberately knotty phrase, bing bing — literally "to be sick of the sickness," or to recognize the disease as a disease. The moment one sees one's false certainty for the defect it is, the defect begins to dissolve; the recognition is itself the healing. The sage is healthy not because he has escaped the human tendency toward presumption, but because he sees that tendency clearly and treats it as the affliction it is. Legge and Goddard differ subtly — Goddard frames it as grieving over one's ignorance of what is knowable — but both preserve the central move: health of mind lies in the honest acknowledgment of the limits and errors of one's own knowing.

"To know that you do not know is best" is the Taoist twin of the Socratic confession that he was wisest only because he alone knew that he knew nothing — the foundation of the whole examined-life tradition in the West. Both make humility about one's own knowledge the gateway to genuine wisdom.

The diagnosis of false certainty as a sickness of the soul resonates with the desert monastics' war on pride as the root of spiritual delusion, and with the Buddhist treatment of fixed views (drsti) as a fetter — the clinging to one's opinions as final being precisely what blocks awakening. Across traditions, the one who is sure he sees is the one most blind.

The healthiest relationship to knowledge is honest awareness of its limits; to know that you do not know is the height of understanding. The real affliction is unexamined certainty — not knowing while being sure you know. The remedy is simply to recognize that false confidence for the defect it is; that recognition is itself the cure.

In an age of confident opinions delivered at speed, this tiny chapter is a precise diagnosis. The "disease" it names is the overconfidence that mistakes information for understanding — the unearned certainty that fills comment threads, boardrooms, and arguments. Its cure is not more knowledge but a particular humility: the capacity to recognize the boundaries of what you actually know, and to treat your own certainty as something to be questioned rather than trusted. The intellectually healthy person is not the one with the most answers but the one who can say, without anxiety, "I do not know" — and who has learned to be wary of the part of the mind that is always sure.