More than 2,500 years ago, Laozi taught it, years later Buddha spoke about it; Hindu deities had also mentioned this mystical light.
Several centuries earlier, the Light was already incorporated in the Book of Changes by the holy sages, so was Tao, yet few seemed to notice or able to relate it with the Way.
Perhaps it is rather hip to discuss yin yang instead of the dark and the light, since the later minted terms (c 300 BC) have been used to represent many other things in the modern world. While yang can represent the light, the Daoist celestial immortal, Lu Dongbin in his Secret of the Golden Flower mentioned it was Guan Yinshi, the student of Laozi, who first revealed the Circulation of the Light meditation.
Why it is called the Circulation of the Light meditation perhaps has significance to the esoteric. Down the millennia those who practice meditation are many and they understand what Qi is. But not many actually understand or know about the mystical light that circulates together with the Qi.
There was once an online article written (the website hosted by two Koreans was since taken down) about a Korean King who was equally mystified who one day decided to give a big reward to anyone in his Court or any scholar who could provide a coherent answer on this mystical light. Apparently no one came forward to claim the reward.
Few meditation teachers know about the mystical light. If their students are ever taught the full circulation of Qi, known as the small heavenly orbit (Xiao Zhou Tian), no one seems to mention about this light.
An elderly ex-colleague of mine was taught the small heavenly orbit by visiting Taiwanese masters for a few years. After asking him about the light, he told me that he could only see darkness during meditation. Knowing his character well and that he can keep secrets, I gave him a few pointers.
A few months later, I asked him about his progress and he told me he could see the light. ‘How was it?’ I asked. ‘Very bright’, he exclaimed with joy.
You see, a neidan practitioner needs proper safeguards during meditation. Apart from humility and heat, the mystical light is also very important. (For further information, please refer to the entry on safeguards placed under Notes on meditation. The same safeguards have been posted in the Taobums forum to point out to a neidan beginner who felt cold during meditation and was seemingly being disturbed by dark or yin spirits.)
According to Lu Dongbin, this mystical light is not in the body alone, nor is it only outside the body.
“Mountains and rivers and the great earth are lit by sun and moon; all that is this light. Therefore it is not only within the body.
Understanding and clarity, perception and enlightenment, and all movements (of the spirit) are likewise this light; therefore it is not just something outside the body.
The light-flower of heaven and earth fills all the thousand spaces.
But the light-flower of the individual body passes through heaven and covers the earth. Therefore, as soon as the light is circulating, heaven and earth, mountains and rivers, are all circulating with it at the same time.”
If you understand clearly what the heavenly immortal had said above, you can go and claim the big reward from the royal Korean court!
But if you are asked to prove it, no adept can. Since how can any neidan adept ever show you the light circulating and which can only be seen within? They can show you heat by touch but they cannot show the mystical light until they have become enlightened. By then, they may not even want to discuss anything, let alone blog!
Yet they may consider it of merit to help the weak and the needy; and heal the sick with their strong heat and the light emitting from their hands. In a way, they could be assisting the gods (include heavenly immortals and Buddhas)?
The third class scholars will laugh and some other scholars may scoff at what has been discussed, but that is Tao. With this entry, perhaps earnest students may have learned something more.