The Nature of Mind Is the Non-Duality of Luminosity and Emptiness
Ultimately, the nature of mind is not just emptiness. Rather it is the non-duality of luminosity and emptiness. The rainbow in the sky or the moon’s reflection in the water may look real, but their illusory nature is actually empty—while in the emptiness they absolutely appear. This is the ultimate reality realized through practicing on the master’s pith instructions. And once realized, one can be called an enlightened being—one who has attained liberation and is free from all suffering.
The nature of the mind cannot be understood as mere emptiness or nothingness. It’s the non-duality of luminosity and emptiness. Luminosity was the main subject of the Buddha Shakyamuni’s third turning of the wheel of Dharma. It means that although the mind has no intrinsic existence, its nature is clarity, so we can see whatever we see and hear whatever we hear.
As said in a sutrayana scripture:
The mind is devoid of mind
For the nature of mind is clear light.
Also from the King of Samadhi Sutra, it can be known that the mind is just like an empty shell:
The reflection of the moon appears
On the surface of a still clear lake,
Yet the reflection has no intrinsic existence—
Such is the nature of all things.
Just as the reflection of the moon has no intrinsic nature, but it undoubtedly appears on the water. Like the rainbow, in the moment of appearing, it is empty; while in the emptiness it absolutely appears. Our mind is the same—although it’s appearing, its nature is empty. So the mind’s nature is to be the non-duality of emptiness and luminosity, which is the utmost reality.
In order to realize these words, one should practice according to the pith instructions from the master. Throughout history, there’re many great masters—monastics and lay practitioners—in India and Tibet, who have achieved such a realization. Thus, they can be called mahasiddhas, the ones who have attained liberation from all suffering of samsara.