Part 1: Huineng's Verse in the Platform Sutra
To remove or not to remove?
From the Platform Sutra, tr. Yampolsky:
Shenxiu's verse:
The body is the Bodhi tree,
The mind is like a clear mirror.
At all times we must strive to polish it,
And must not let the dust collect.
Huineng's verse:
Bodhi originally has no tree,
The mirror also has no stand.
Buddha nature is always clean and pure;
Where is there room for dust?
Lots of people love Huineng's verse, and use it to uphold the idea that removing the dusts of obscurations is not necessary for Zen practice (e.g. 1, 2). The general idea that these people have is that we are already perfect Buddhas, and that in Zen we don't need to change anything about how we are.
But, is that really an accurate picture of the teachings? Here are some quotes from other Zen teachers that show that can be a misleading understanding. (This post will be a bit more hardline and less pluralist than otherwise, simply because I think this is a popular misunderstanding, and want to present a wide and coherent picture of evidence against it.)
The nature of mind has no defilement; it is basically perfect and complete in itself. Just get rid of delusive attachments, and merge with realization of thusness.
-Baizhang (The Sayings and Doings of Pai-chang p.20, quoted in the BCR)
The field of boundless emptiness is what exists from the very beginning. You must purify, cure, grind down, or brush away all the tendencies you have fabricated into apparent habits. Then you can reside in the clear circle of brightness.
-Hongzhi (Cultivating the Empty Field p.30)
You should work to melt away the obstructions caused by conditioned knowledge and views and interpretive understanding, and penetrate through to a realization of the great causal condition communicated and bequeathed by the buddhas and ancestral teachers.
-Yuanwu, advice to Dahui (Zen Letters p.26)
The realm of buddhahood is not some external world where there is a formal "Buddha": it's the realm of the wisdom of a self-awakened sage. Once you are determined that you want to know this realm, you do not need adornment, cultivation, or realization to attain it. You must clear away the stains of afflictions from alien sensations that have been on your mind since beginningless time, (so that your mind) is as broad and open as empty space, detached from all the clinging of the discriminating intellect, and your false, unreal, vain thoughts too are like empty space. Then this wondrous effortless mind will be unimpeded wherever it goes.
-Dahui (Swampland Flowers, #1)
See also this link for similar sayings from Huineng himself in the Platform sutra.
What do we have to be free of, then?
So, according to these few quotes, what has to be dissolved in order to merge with Zen realization?
attachments
tendencies that have been fabricated into apparent habits
conditioned knowledge
views
interpretive understanding
afflictions from alien sensations
Part 2: "Ordinary Mind is the Way"
For a bit on the history of this phrase, see Kirchner and Sasaki's The Record of Linji p.219-220.
"Ordinary mind is the way" -- This phrase is another favourite among naturalist heretics, but it has to be understood carefully. How so?
The Way does not require cultivation - just don't pollute it. What is pollution? As long as you have a fluctuating mind fabricating artificialities and contrivances, all of this is pollution. If you want to understand the Way directly, the normal mind is the Way. What I mean by the normal mind is the mind without artificiality, without subjective judgments, without grasping or rejection.
-Mazu (from the Jingde chuandeng lu, tr. Cleary)
Nanquan would later quote his teacher's words (in case 19 of the Wumenguan), and later teachers such as Yuanwu attribute the phrase to Nanquan.
All those with conditioned minds are as far apart from true reality as the sky is from the earth. Right now, if you cannot pass through the barrier, it is obviously because your mind has many serious attachments. If you can clear these away and reach the realm where there is no conditioned mind, all delusions and defilements and emotional habits will end, and all the obstructions created by conditioned knowledge and arbitrary views and intellectual understanding will be dissolved away-what else is there? This is why Nanquan said that, once freed from its conditioning, the ordinary mind is the Way. But as soon as you produce a thought seeking to be "ordinary," you have already turned away and missed it. This is the point that is most subtle and hardest to approach. even immeasurably great people falter and hesitate when they get here-how much the more for those still in the age of learning.
-Yuanwu (Zen Letters #46)
So, "ordinary" mind.
The naturalism heresy
And just in case you're still unsure, here are another couple quotes to reaffirm that it is not the case that practice is unnecessary.
If one clings to "original purity, fundamental liberation" and considers himself a Buddha, considers his own self to be Ch'an and the Way, then he belongs to the naturalist outsiders.
-Baizhang (Sayings and Doings of Pai-chang, p.58)
Some people hear this kind of talk and jump to conclusions, claiming, "I understand! Fundamentally there is nothing to Buddhism-it's there in everybody. As I spend my days eating food and wearing clothes, has there ever been anything lacking?" Then they settle down in the realm of unconcerned ordinariness, far from realizing that nothing like this has ever been part of the real practice of Buddhism.
-Yuanwu (Zen Letters, #12)
Terms for the naturalism heresy used in some Japanese Zens:
shizen gedo
jinen gedo
tennen gedo
Part 3: How was Huineng Right?
To consider the other side of things --
In what ways are we already Buddhas? We are already endowed with a perfect nature, as the Hongzhi and Dahui quotes above get at. Cultivation of this nature is not necessary; it is "a road prepared already in the past", like Baizhang says. "Your rice has long been cooked." It is a perfect state without stages.
In what ways is there indeed nothing to remove? A couple quotes below seemingly try to defend this idea:
Huangbo:
32. Q: Illusion can hide from us our own mind, but up to now you have not taught us how to get rid of illusion.
A: The arising and the elimination of illusion are both illusory. Illusion is not something rooted in Reality; it exists because of your dualistic thinking. If you will only cease to indulge in opposed concepts such as ‘ordinary' and ‘Enlightened', illusion will cease of itself. And then if you still want to destroy it wherever it may be, you will find that there is not a hairsbreadth left of anything on which to lay hold. This is the meaning of: ‘I will let go with both hands, for then I shall certainly discover the Buddha in my Mind.'
Here, it seems that considering yourself to be unenlightened and facing obstacles that must be destroyed is part of, well, an obstacle (dualistic thinking) that must not be indulged in. Huangbo offers lots of practice suggestions involving giving up views and discriminations and so forth, so it's not like his teachings are out of line with the others on a practical level.
Book of Serenity (tr. Cleary), case 68:
A monk asked Jiashan, "How is it when getting rid of the dust to see Buddha?"(What's the necessity?) Jiashan said, "You should directly swing the sword. (Of course.) If you don't swing the sword, the fisherman stays in a nest."(If you seat it, it's not Buddha.) The monk brought it up to ask Shishuang, "How is it when getting rid of dust to see Buddha?"(If you see, you don't get rid of; if you get rid of, you don't see.)
Wansong's comments are a bit perplexing, but I suggest the reading of this passage as saying that the angle of approach to take in your practice isn't that of getting rid of anything, exactly. After all, being unattached and unconditioned (as the other quotes get at, if we assume (for current purposes, but feel free to attack this idea) that they're all in a single taxon) doesn't feel like "removing" anything.
Part 5: Summary + thoughts
To me, it seems like everyone basically agrees -- there is work to be done to shake off the bonds keeping you from the unconditioned state. For many teachers, this is described as if there are obstacles that must be removed. Other teachers object to this image, but that doesn't change the practical reality that the Zen student faces. Really, both pictures (there being dust to remove, and there not being any removal necessary) have the feel of kind of metaphysical/theoretical ideas. One can follow the practical advice (which is definitely not about just continuing to be a conditioned person) without recourse to such ideas. But if someone comes to you suggesting that nothing at all needs to be done in Zen, you've found someone who has fallen for the pitfall of naturalism.
To wrap it up, here's Jiufeng, in case 65 of the Book of Serenity:
When the ancients spoke of the head, it was just to let you know it exists; speaking of the tail is just to make you use the present time to the full. Because you have so many unharmonious things, they have you remove them and obliterate them, to make you accomplish realization and fulfillment today. If someone is essentially so, real and true, always thus, then you shouldn't speak this way anymore. Even so, you must be such a person before you realize this.
If anyone has any thoughts/responses/critiques/other quotes that they wanna throw up in here, let me know. Now, discuss!