Thomas Cleary has included a number of useful teachings in his book Teachings of Zen. The tendency with any book is to read it then forget a lot of its contents. When reading about Zen Buddhism we miss a lot even if we go through the book or a discourse a number of times.
For the last week I have been wondering to myself that if I were asked to recommend one teaching from a Zen master, which one would it be? Based on my own enlightening experience it would have to be this teaching by Yuan-hsien (1618–1697).
There are not many arts to Zen study; it just requires knowing your own true mind. Now observe that within this body the physical elements combine temporarily, daily heading to extinction: where is the true mind?
The flurry of ideas and thoughts arising and passing away without constancy is not the true mind.
That which shifts and changes unstably, sometimes good, sometimes bad, is not the true mind.
That which wholly depends on external things to manifest, and is not apparent when nothing is there, is not the true mind.
The heart inside the body which cannot see itself, blind to the internal, is not the true mind.
What is unaffected by feelings outside the body, cut off from the external, is not the true mind.
Suppose you turn the light of awareness around to look within, and sense a recondite tranquility and calm oneness; do you consider this the true mind? You still do not realize that this recondite tranquility and calm oneness are due to the perceptions of the false mind: there is the subjective mind perceiving and the object perceived—so this recondite tranquility and calm oneness belong to the realm of inner states. This is what is meant by the Heroic Progress Scripture when it says, "Inwardly keeping to recondite tranquility is still a reflection of discrimination of objects." How could it be the true mind?
So if these are not the true mind, what is the true mind? Try to see what our true mind is, twenty-four hours a day. Don't try to figure it out. Don't try to interpret it intellectually. Don't try to get someone to explain it to you. Don't seek some other technique. Don't calculate how long it may take. Don't calculate the degree of your own strength —just silently pursue this inner investigation on your own: "Ultimately, what is my own true mind?"