The rise of southern doctrine
The philosophical significance of what Shenhui's "Southern" doctrine brought to Chan has been described as nothing less than a revolution. A modern Zen scholar, Hu Shih, has claimed that Shenhui's revolution produced a complete replacement of Indian Buddhism with Chinese principles, keeping only the name. Shenhui, he says, swept aside all forms of meditation or dhyana and replaced it with the concept of no-mind: the doctrines of "absence of thought" and "seeing into one's original nature."
It's worth noting as well that the Northern school did not lose importance in Chinese society due to its philosophical views but rather its closeness to the emperor at a time of social upheaval.
Although Shenhui is somewhat vague about exactly what practice should replace meditation, he seems to have rejected meditation in the sense of the word as we use it. Instead of methodical endeavors designed to promote religious progress he recommends a change of point of view leading to non-attachment. According to Shenhui:
When thus my friends are told to discard as useless all they have learned before, then those who have spent fifty or more, or only twenty years practicing meditation, hearing this, might be very much puzzled . . . . The Nirvana Sutra says, "To get rid of your passions is not Nirvana; to look upon them as no matter of yours, that is Nirvana."
And how do we reach this state of recognition without attachment? The way is to find our original state, in which we were naturally unattached to the surrounding world. The way is to mentally disassociate ourselves from the turmoil of society that surrounds us and look inward, touching our original nature. In this way, both prajna and samadhi, awareness and noninvolvement, which have been described as the active and passive sides of meditation, are achieved simultaneously.
Now let us penetrate to that state in which we are not attached. What do we get to know? Not being attached we are tranquil and guileless. This state underlying all motions and passions is called samadhi. Penetrating to this fundamental state we encounter a natural wisdom that is conscious of this original tranquility and guilelessness. This wisdom is called prajna. The intimate relation between samadhi and prajna is thus defined.
If now you penetrate to that state in which your mind is not attached, and yet remains open to impressions, and thus are conscious of the fact that your mind is not attached, then you have reached the state of original blankness and tranquility. From that state of blankness and tranquility there arises an inner knowledge through which blue, yellow, red, and white things in this world are well distinguished. That is prajna. Yet no desires arise from these distinctions. That is samadhi.
It follows that freedom from attachment (to external things, which replaces meditation in Chan Buddhism}, enables you to look into the heart of all the Buddhas of the past, and yet it is nothing else than what you yourselves experience today.
Chongyuan: "Were Zen master Huineng and Zen master Shenxiu not fellow students of Hongren ?"
Shenhui: "They were."
Chongyuan: "Since they were fellow students, are their teachings the same or not?"
Shenhui: "Not the same."
Chongyuan: "Since they were fellow students, why are their teachings not the same ?"
Shenhui: "I will now explain their difference. It's because Zen master Xiu taught people to 'focus the mind and enter concentration. Stop the mind and observe purity. Give rise to mind that shines outward. Collect the mind inside and bear witness to it.' For this reason their teaching is different."
Chongyuan: "Why is it that Zen master Neng does not teach [the practices taught by Zen master Xiu] ? What are his practices ?"
Shenhui: "The practice of Shenxiu is to harmonize and subdue the mind."
Chongyuan: "Then should one not [perform the practices taught by Shenxiu] ?"
Shenhui: "These are the methods of the ignorant. Zen master Huineng's practice is found apart from the two methods of 'subduing' or 'not subduing.' This is why is says in the sutra, 'mind does not abide within, nor is it external.' It is in quiet sitting. When one sits in this manner, one realizes buddhahood. In the six generations that have come before, not a single person performed the practices of Shenxiu. They are entirely different."
By redefining meditation, Shenhui had "laid the foundations of Chinese Zen which was no Zen at all.'' As Shenhui now described meditation or dhyana:
Sitting motionless is no dhyana; introspection into your own mind is no dhyana; and looking inward at your own calmness is no dhyana. . . . Here in my school, to have no thoughts is sitting, and to see one's original nature is dhyana (Chan).
Sweeping aside Buddhism
The scholar Hu Shih described this new teaching as a Chinese revolt against Buddhism.
Perhaps the most revolutionary thing about Shenhui's approach was that it seemed to eliminate the need for all the traditional apparatus of Buddhism. It had little or nothing to do with organized religion and even less connection with the mountains of Indian philosophy that had gone before.
A thousand years of Indian thought had been distilled down to a single truth: the realization of our original nature comprises enlightenment. If this were taken at face value, then there was no longer any need for the Buddhist community, the sutras, the chanting, even meditation. There was, in fact, no longer any need for Buddhism. It had been reduced, as the Chinese scholar Wing-tsit Chan has observed, to a concern for the mind alone.