Tao Te Ching · Ch. 71

知不知,尚矣;不知知,病也。聖人不病,以其病病。夫唯病病,是以不病。

Zhī bù zhī, shàng yǐ; Bù zhī zhī, bìng yě. Shèng rén bù bìng, yǐ qí bìng bìng. Fú wéi bìng bìng, shì yǐ bù bìng.

To know that you do not know is the highest. Not to know while thinking you know — that is a sickness. The sage is not sick because he treats his sickness as sickness. Only because he treats his sickness as sickness does he remain not-sick.

— Tao Te Ching 71

Source: Wang Bi edition (Chinese) + Hanyu Pinyin transliteration