The Theory of Yongsin — The One Character That Restores Balance
Go a little deeper into Saju and you will inevitably meet the concept of the 'yongsin,' or useful god. The yongsin is the single most beneficial element that restores balance among the eight characters, the key to answering the question, 'What acts as medicine for this chart?' Once you know your yongsin, the grain of the colors, directions, careers, and timing that suit you falls into place along with it.
What Is the Yongsin?
The yongsin refers to the element that pulls a chart back into balance when the overall energy of the Saju leans too far in one direction. Because everyone is born with a different distribution of the five elements across their eight characters, each person's yongsin is also different. Determining the yongsin is the hardest and most important step in reading a chart. Once this one element is settled, the elements that help it (the favorable god) and those that harm it (the unfavorable and hostile gods) are also sorted out, and the direction of one's life comes into sharp focus.
Eokbu Yongsin — Reduce the Strong, Support the Weak
The most fundamental method is eokbu, meaning 'to restrain and to support.' If the day master, which represents you, receives much help from its surroundings and is therefore strong (singang), the yongsin becomes the element that drains off the excess force — the energy you produce or the energy you control. Conversely, if the day master stands alone and is weak (sinyak), the yongsin becomes the element that supports and produces you. It works just like a scale: lighten the heavy side and add strength to the light side to bring the two into balance.
Johu Yongsin — Adjusting for Cold and Heat
When eokbu alone is not enough, johu — 'adjusting the climate' — is considered alongside it. Depending on the season of the birth month, a chart may be too cold (winter, water energy) or too hot (summer, fire energy), and the element that corrects this imbalance of cold and warmth becomes the yongsin. For a chart born in winter, warm fire energy acts as medicine; for a chart born in summer, cool water energy does. It is the same logic by which a person seeks fire when cold and water when hot.
Tonggwan and Byeongyak — Clearing the Blockage
Beyond these, when two forces stand in taut opposition and clash, there is the tonggwan yongsin — an element used to connect and channel between them. For instance, when metal and wood collide fiercely, the water that bridges them (metal produces water, water produces wood) becomes the tonggwan yongsin. And when a chart contains a character that acts as a distinct 'illness' (byeong), there is also the byeongyak yongsin, the element that serves as the 'medicine' (yak) to treat that illness. All of these follow the principle of clearing a blocked flow so that it can circulate.
Putting the Yongsin to Use in Life
The yongsin does not stay a matter of theory; it can be carried into daily life. Keeping colors that correspond to your yongsin element close by, making use of its direction, and choosing work in a field that resonates with its energy is thought to make up for what you were born lacking. In the major and annual luck cycles, the periods when the yongsin element enters are generally read as times when the flow runs well. That said, the yongsin must be judged carefully by weighing the entire chart, so it is best taken as a reference for your broad direction.
The yongsin is like a compass that threads a complicated chart into a single direction. If you are curious about your chart's strength or weakness, your lacking element, and the colors and directions that fill it, cast your own chart from your birth date and time and see for yourself.