Those who understand others is wise, those who understand oneself is enlightened.

-> Externally we seek to understand others (e.g. our family, company, country); internally how many seek to understand our own “self”?  We might understand our personality, including strengths and weaknesses, but more fundamentally, what is this personality?  Where does it come from and how does it arise?  Can it last or is it temporary?  All in all, what am “i”?

Those who conquer others has force, whose who conquer oneself is strong.

-> In conquering others, we can use external force such as armies, allies and money.  In conquering our “self”, internal strength is needed: we need courage to face our “self” and the world, willlingness to work through habits and believe systems, acceptance of our limitations and short-comings, reason to contextualize and understand, kindness to love and to forgive, and humility to see and surrender our attachments and illusions.   Conquering others by force is temporary (as can be seen in world history), while internal mastery is forever.

Those who content is rich.

-> With spiritual maturation, we become more appreciative to the richness of life.  Those who are thankful are rich.

Those who preserve in advancing has will.

-> Cultivation is a life-long dedication, persistence is essential.

Those who stay with their root can last. Life beyond death is real longevity.

-> Our real root is not subjected to changes and the temporariness of physical life, when we realize our true nature which is beyond physical death, we reach real longevity.

* * *

Chapter 33 Discussion:

This chapter starts by describing the different between external power and internal strength, that spiritual studies require one to direct our attention to within.  When we develop our internal strength, face life with gratitude, and dedicate our life to the fulfillment and upliftment of all (including ourselves), then our contentment with life expands.  Eventually we realize our everlasting root, beyond the limitations of physicality and changes, we are finally home.

Bilingual version of Ch33: https://www.lisiming.net/philosophy/chinese-philosophy/daoist/daoist-philosophy/dao-de-jing-core-33-chapters/ddj11-3/