This world has aspects of both yang and yin.
The myriad heavens and worlds are yang, representing life and solidity, while the Netherworld is yin, representing death and intangibility.
However, while there are countless heavens and worlds, there is only one Netherworld.
As the saying goes, "The Dao produces one, one produces two, two produce three, and three produce all things." It is also said, "When yang reaches its peak, yin is born; when yin reaches its peak, yang is born."
It is said that when the myriad heavens and worlds were first born, the Netherworld did not exist.
As the myriad heavens and worlds developed, the Netherworld gradually came into being, appearing to be a case of yang producing yin.
