Lao Tzu (Laozi) lived some time in the 6th century BC, during a time of political turmoil in the Spring and Autumn Period.  His name is a title meaning "Wise Old Man."

 Seek personal harmony.

His book, Dao De Jing (The Way of Virtue) is written in poetic, metaphorical language.  Some key concepts:

• Existence is constantly changing, and cannot be defined.
• Allow nature's example to guide your way.
• Passiveness (non-action) is real strength.
  
• Everything contains elements of its opposite (yin & yang).
  

• The emptiness in the center of the wheel is what holds it to the axle.
• Be like the grass, not the oak.
• What is more yielding than water?  Yet water can cut rock.
• Why are people rebellious?  Because the rulers interfere too much.