Mind is Buddha
Like Daoxin, Shitou taught that "the mind is Buddha"—a central teaching in early Chan.
The key point of my teaching comes from Buddha. We concentrate on actualizing Buddha's insight, not on making progress in meditation. The mind is the Buddha. Buddha and common people, enlightenment and delusion have different names, but they have the same origin. You've got to study your minds first! Human nature in itself is neither good nor bad. Sages and common people have the same complete nature. There isn't some special way to apply this theory to reality. Your own mind reflects the entire world. Flowing water doesn't have some beginning or ending, nor the changing moon, nor the moon's reflection on the water. If you understand this, you have all that is necessary.
This teaching is not saying that our mind and the mind of Buddha are identical, nor that we can find Buddha-nature (Buddha-mind) is inside our mind. For Shitou and, as we will see in the next lesson, Mazu, the human mind in its original and essential state is itself Buddha-nature.
Daowu ( a student of Shitou): "Who understands the teachings of Cao Xi?"
Shitou: "He who understands the teachings of Buddha."
Daowu: "Have you got it?"
Daowu: "Why not?"
Shitou: "Because I don't understand Buddhist teachings." (Buddha's teachings are not to be understood through conventional understanding.)
Daowu: "How then can I be free?"
Shitou: "Who's holding you captive?"
Daowu: How can I get to the Pure Land?"
Shitou: "Who's making you impure?"
Daowu: "What is Nirvana?"
Shitou: "Who is it that places you in birth-and-death?"
A monk: "Why did the First Ancestor come from the west?"
Shitou: "Ask the stone pillar."
The monk: "I'm only a student; I don't understand."
Shitou: "I don't understand either."
Dadian: "People in ancient times said that it is wrong to believe in the Path and wrong not to believe in the Path. Would you explain this to me?"
Shitou: "There is nothing right or wrong, so what is there to explain? . . . . Can you talk about the future without using your throat and lips?"
Shitou: "In that case you can be my student."
Daowu "What is the basic principle of Buddhism?"
Shitou: "You already have it."
Daowu: "Is there a turning point upward?" (Is there a way to understand this further?)
Shitou: "White clouds pass freely through the sky." (Against a blue sky of emptiness, phenomena pass without obstruction.)
Daowu: "What is Chan?"
Shitou: "This rock."
Daowu: "What is the Path?"
Shitou: "That piece of wood."