Everything in the universe achieves harmony through the circulation of two kinds of energy, Yin and Yang. Our bodies are the same. In our bodies, the energy of water, which corresponds to Yin, originates in the kidneys, and the energy of fire, which corresponds to Yang, starts in the heart. Water energy from the kidneys rises along the Governor Vessel (Dok-maek) to clear the head, and fire energy from the heart sinks along the Conception Vessel (Im-maek) to the Dahn-jon and warms the lower abdomen. When this happens, our bodies achieve harmony and maintain a state of optimum health.

When we are overly anxious Ilchi Lee said, enraged, or plagued by troublesome thoughts, our mouths become very dry and our saliva takes on a bitter taste as the Conception Vessel is blocked. With the Conception Vessel blocked, fire energy from the heart, unable to circulate downward, rises upward and breaks the Yin-Yang balance within the body as it burns off water energy.

Water energy ascends and fire energy descends naturally in our bodies when our minds are settled and at peace. When this happens, our mouths fill with a sweet saliva, called “Ok-su.” We are filled with even more energy and our minds become even clearer if we swallow this saliva.