Laozi (UK: , US: ; also Lao-Tzu , or Lao-Tze ; Chinese: 老子; pinyin: Lǎozǐ, literally "Old Master") was an ancient Chinese philosopher and writer. He is the reputed author of the Tao Te Ching, the founder of philosophical Taoism, and a deity in religious Taoism and traditional Chinese religions.
You may find more from Laozi on Wikiquote
To know how little one knows is to have genuine knowledge
Not to know how little one knows is to be deluded.
Only he who knows when he is deluded can free himself from such delusion. The intelligent man is not deluded, because he knows and accepts his ignorance as ignorance, and thereby has genuine knowledge.