Zen Master Dogen once said, "As long as we only think about the buddha-dharma with our minds we will never grasp the Way, even in a thousand lifetimes or a myriad of eons. When we let go of our minds and cast aside our views and understandings, the Way will be actualized. One sage clarified True Mind (Reality) when he saw peach blossoms and another realized the Way when he heard the sound of tile hitting a bamboo. They attained the Way through their bodies. Therefore, when we completely cast aside our thoughts and views and practice shikantaza, we will become intimate with the Way. For this reason, the Way is doubtlessly attained through the body. This is why I encourage you to practice zazen wholeheartedly."

Dogen is referring here to the story of 9th Century Master Lingyun Zhiqin.  Legend has it that Lingyun had realization upon seeing peach blossoms.  He then wrote a poem:

For thirty years I have looked for a sword.
Many times leaves fell, new ones sprouted.
One glimpse of peach blossoms,
Now no more doubts - just this.

A simple glimpse of peach blossoms and Lingyun enters the valley of endless spring.  Life, death, buddhas, demons, enlightenment, and delusion all vanish with the falling away of body and mind.  

But as the late John Daido Loori points out, "Flowers bloom and abound each and every spring - why doesn't everyone who sees them attain the Way?  What does Lingyun see that helps him to realize the Way?"  

I suspect Daido is being mischievous and throwing us a red herring.  I say Lingyun only saw that which anyone else could see - what was different was not the perception, but the perceiver.  Through his practice with Master Guishan, Lingyun had arrived at that still, quiet place where the sight of peach blossoms could awaken him to true reality.  The Way was revealed to him physically - through both his practice of shikantaza and through the sense organs of his eyes.  The mind had nothing to do with it.  There was nothing to learn, nothing to be taught.  There was only that which could be experienced physically.

How then, does one teach that which does not involve the mind?  How does one find a teacher who has nothing to teach?  Lingyun once told an assembly of monks, "No matter where it is that those of high ability permanently abide with their good companions of the Way, and make the Truth evident by renouncing the world, that place is where the Dharma is revealed."

Four hundred or so years later, Dogen said much the same thing: "There are three steps in the manifestation of virtue. Firstly, it becomes known that a person is practicing the Way. Next, people who aspire to the Way come to that person. And lastly, people learn the Way and practice with him in the same way. This is called the manifestation of the virtue of the Way."