In Korean medicine, sleep is not seen merely as a time for the body to rest, but as an essential process for restoring stability to our mind and spirit. In particular, Donguibogam looked into the state of our ethereal soul (hon) and corporeal soul (baek) through the phenomenon of dreaming. It stated that 'dreams are the wandering of the ethereal soul and the corporeal soul.' Here, it is easy to understand the ethereal soul as the energy governing our mental activities, emotions, and thoughts, while the corporeal soul governs the functions of the five viscera and six bowels as well as physical sensations.
When we sleep, this ethereal soul must be stored and settled in the liver before we can achieve deep and comfortable sleep. However, what happens if our minds are depressed, full of worry, or constantly anxious due to stress? The ethereal soul, which ought to stay in the liver, cannot remain in its proper place and floats around inside the body, much like a child who has lost a place to rest. When the ethereal soul is unstable like this, it becomes difficult to fall asleep, and even after falling asleep, one dreams frequently or suffers from nightmares. The saying, 'Having many dreams means the ethereal soul is not at peace,' carries precisely this meaning.
Modern depression is very closely linked to this instability of the ethereal soul. When the mind feels stifled and depressed for a long time, the circulation of qi in our bodies becomes blocked, and the liver qi, which regulates emotions, is particularly prone to stagnating. When liver qi stagnates, heat is generated, and this heat is transmitted to the heart, agitating the spirit (sin) of the heart. Because the heart governs the spirit and consciousness, both body and mind become uneasy, creating a vicious cycle where sleep does not come at night and one feels lethargic and depressed during the day.
If this state continues, body fluids are consumed, yin becomes deficient, and yang qi becomes relatively floating and agitated. At night, it is natural to fall asleep as yin qi becomes abundant, but when yin becomes deficient, yang qi floats upward, generating deficiency heat that disrupts sleep. Many of you have likely experienced feeling drained and down during the day, only to become wide awake once night falls. Long ago, Donguibogam delicately revealed the effects that mental suffering has on the circulation of qi and blood in the body, describing the resulting sleep disorders and changes in dreams. It offers a wise perspective that allows us to reflect on whether the harmony between mind and body has broken down, rather than simply viewing it as a sleep issue alone.
