During my early days as an impressionable Internet Buddhist, circa 1995, I recall a discussion in an AOL chatroom where the most sapient among us insisted that the notion of light being an important part of enlightenment was folly. Other sagacious sutra readers in the room were insistant that the term enlightenment should be abandoned altogether because it planted in our minds misdirecting ideas of what enlightenment/satori/awakening was. For years thereafter, I clung to that appraisement: Enlightenment is ineffable. For us to impose preceptions of it that give it flavor or color or feel would cause us to misidentify markers in our spiritual advancement, sending us off on muddy time-wasting slogs through the barren marshes of error.
Today, I have come to think that light is important: its rays filling the room; its beams serving as a guide to anyone's quest to eliminate suffering in the adventure of life. Hui-neng, the great C'han master, said in his Platform Sutra, "Learned audience, to what are meditation and wisdom analogous? They are analogous to a lamp and its light. With the lamp, there is light. Without it, it would be dark. The lamp is the quintessence of the light and the light is the expression of the lamp. In name they are two things, but in substance they are the same. It is the same case with meditation and wisdom."
Zen Master Ejo, Dogen's disciple, in the chapter "Absorption in the Treasury of Light" in his Shobo Genzo Zuimonki wrote "Buddha said, 'This light of lights is not blue, yellow, red, white, or black. It is not matter, not mind. It is not existent, nor nonexistent. It is not a phenomenon resulting from causes. It is the source of all Buddhas, the basis of practicing the Way of enlightening beings, fundamental for all Buddhists.'"
It is only in the last one hundred years, thanks to the creative intelligence of Albert Einstein, that we have come to better understand this light whatever-it-is that pervades the universe -- Buddha's remark, quoted by Ejo, being intuitively correct, but far, far ahead of science!
People commonly misunderstand light, thinking it this hybrid thing -- part wave, part matter -- that travels at an incredible velocity, the so-called Speed of Light. But light doesn't dawdle at the Speed of Light; unimpeded, it traverses the universe instantly. It is untouched by time. It is only from the perspective of lumpy, time-bound humans that light travels at 186,000 miles/second. If it were possible to chain our wrist to a beam of light, we would be everywhere in the smallest segment of a moment. Light is indeed as Buddha described it, "not matter, not mind. It is not existent, nor nonexistent. It is not a phenomenon resulting from causes."
According to currently configured theory of everything, M Theory, a photon of light is a non-looping vibrating string, atuned to the laws of harmonics, bounded, as sentient beings are, between two impassible membranes [that bar us from other dimensions we cannot perceive], leaving us in the universe we know, existing in the three dimensions of space. While sentient beings travel a life's journey on an arrow of time, light does not. Light is not subject to time; a beam of light is immutable.
From the Tibetan Book of the Dead we are told that the first stage of the Bardo -- the Chikai, the bardo of dying -- begins at death and lasts from a half a day to four days. During this period, the dead person realizes he no longer has a body. An ecstatic experience pervades the consciousness of the departed, called the "Clear White Light." It is written that everyone gets at least a glimpse of this light, but that the more spiritually advanced will see it longer and go beyond to a higher level. An average person will drop into a lesser state, the secondary "clear light."
It is believed that the "Clear White Light" is the light from all enlightened ones, indistinguishable from everyone's true essence. Ejo wrote something parallel regarding the treasury of light: "[It] is the root source of all Buddhas, the inherent being of all living creatures, the total substance of all phenomena, the treasury of the great light of spiritual powers of complete awareness. The three bodies [mind belonging to the Arhats, Pratyekabuddhas, and Bodhisattvas], four knowledges [realizing their liberation], and states of absorption [in mystic or meditative union with ecstacy] numerous as atoms in every aspect of reality, all appear from within this."
Those who have had a near-death experience describe something just like the "Clear White Light," and have other experiences which track and seem to validate the stages of the bardo described in the Book of the Dead.
This is written about Amitabha Buddha: "The splendor of His brilliant light is beyond mind. The light of His brows illuminates a hundred worlds. His eyes are pure brilliant light, limitless like the oceans. In Amitabha's realm of infinite light, all beings are transformed And Enlightened into countless Bodhisattvas and Buddhas. His Forty Eight Vows ensure our liberation In Nine Lotus Stages we reach the ultimate shore of Enlightenment. Homage to the Buddha of the Pure Land, Compassionate Amitabha Buddha."
Near the end of "Absorption in the Treasury of the Light," Ejo wrote:
This is the light in which the ordinary and the sage, the deluded and the enlightened, are one suchness. Even in the midst of activity, it is not hindered by activity. The forest and the flowers, the grasses and the leaves, people and animals, great and small, long and short, square and round, all appear at once, without depending on the discrimination of your thoughts and attention.. This is manifest proof that the light is not obstructed by activity. It is empty luminosity spontaneously shining without exerting mental energy.
This light has never had any place of abode. Even when buddhas appear in the world, it does not appear in the world. Even though they enter nirvana, it does not enter nirvana. When you are born, the light is not born. When you die, the light is not extinguished. It is not more in Buddhas and not less in ordinary beings. It is not lost in confusion, not awakened by enlightenment. It has no location, no appearance, no name. It is the totality of everything. It cannot be grasped, cannot be rejected, cannot be attained. While unattainable, it is in effect throughout the entire being. From the highest heaven above to the lowest hell below, it is thus completely clear, a wondrously inconceivable spiritual light.
If you believe and accept this mystic message, you do not need to ask anyone else whether it is true or false; it will be like meeting your father in the middle of town. Do not petition other teachers for a seal of approval, and do not be eager to be given a prediction and realize fruition.
To study enlightenment is to study the self. To study the self is to forget the self. To forget the self is to be one with all things. To be one with all things is timeless enlightenment. And this timeless enlightenment continues forever, it is a ceaseless process, absolutely perfect, and fully complete at every moment of its being, yet also unfolding endlessly ...