The Three (Trinity) — heaven, Earth, humanity — is the outcome of the movement from Tao/Taiji.

To Laozi it was Tao, One (Qi), Two (Yin + Yang), Three.

To Zhou Dunyi it was Taiji/Tao, Two (Yin Qi, Yang Qi), five elements, myriad creatures.

The correspondences summarize all kinds of relationships — from a human body to the environment, from sensation to philosophy. Nature, society, and humanity form a trinity.