There has been an ancient tale which tells of a Buddhist who, once upon a time, summed up his experiences through long-time silent sitting exercise, saying, "My form is as a tree trunk, my heart is as clean as like a looking-glass. I have been dusting my heart every now and then lest it should incur even one slight stain."

Upon this, Liu Chu, a great saint, at once pointed to the depth of the truth, saying, "Originally, there existed no tree, nor anything such as a mirror. When there is nothing at all, how to incur dust?"

An analogy can be given to explain the relationship between Heart and Innate Nature.

The Heart works like the Earth, while our Innate Nature the emperor.

Or in other words, our Heart serves as like a vast territory while our Innate Nature the king holding reins over it.

Innate Nature takes residence in the Heart, and depends upon the Heart for it's existence.

If there is no Heart, there can be no Innate Nature.

Disciplining the Heart means getting rid of all desires and passions, so as to make a clean sweep of the Heart, and to restore the True Heart.

The True Heart - The Heart which is pure, virginal and free from any contamination by desires and passions.

Heart, like a brand-new mirror stationed in one place, is gradually dimmed by dust as time passes by,
no matter how polished it originally was.

At the beginning, the Heart had its own nature composed of quietude and emptiness.

When material desires aggressively intrude themselves upon the pure region of the Heart, this pure nature begins to be disturbed and broken into pieces and later there is almost nothing left resembling the former qualities it was originally endowed with.

This circumstance is just like that of a stream:

During its winding and struggling course the wind begins to swirl it about, and no matter how clear and pure its source is, the mud and sand tumble about to mingle and mix with it; thus changing it’s original pristine nature.

Water has its original nature of stillness, but it begins to be involved in motion, for wind is blowing and sweeping constantly across its surface.

Originally, water is as clear as a crystal, but it becomes muddy, since earth and sand keep tumbling into it.

Quieting the waves the water naturally will become still and motionless; depositing the earth and sand, the water is sure to resume its nature of lucidity.

Lucidity is the noumenon of water, while stillness its Innate Nature.

So it is also with the Heart.

Many practitioners engaged in the pursuit of Tao often mistake Acquired Wisdom (with Yin Congenital Mind-Will at its root) for Noumenon.

As a result, the foundation gained from self cultivation will be laid biased and all efforts made in vain, even though later they follow the course of Cultivating Nature and Disciplining Heart resolutely.

A minute mistake is capable of causing utter failure.

Never one idea arising in the Lower Elixir Field promises a good beginning for successful pursuit of Tao.

You may think that the heart, once becoming so lifeless, will has nothing different in comparison with inanimate ashes and stone.

But, in reality, in no circumstances does it go on in this way, owing to the fact that sudden inspiration as well as divinity---coming from nowhere and cannot be courted on purpose---will come on the scene when the heart gives up all acquired wisdom and knowledge.