In ancient Chinese philosophy 

Nature has opposite energies  

The yin and the yang co-exist  

Their interplay 

Keeps things in harmony    

Dark and bright  

Alternating to form  

Day and night  

Male and female  

Complementary  

In the procreation of life  

In society there is  

Good and evil  

In our lives 

The same two forces  

Flow back and forth  

These contrasting qualities  

Are not mutually exclusive  

They form dualities  

And seek stabilities 

In all creation

By Shih-Fang Wang

From: United States