A student once came to a teacher and said, "I have studied the teachings. I understand Oneness; that everything is one. I understand Manifold; that reality is fractal and differentiated. But how can both be true at the same time?"
The teacher said, "Tell me about your hand."
"It has five fingers."
"Is your hand five things or one thing?"
"Both."
"And does that bother you?"
The student paused. "No."
"Then why does it bother you when I say the universe is one and many?"
The student sat with this for a long time. Then she said, "Because with my hand, I can see both at once. With the universe, I can only see one at a time."
"Ah," said the teacher. "Now you have found the real question."
This is crosstruth: the recognition that the universe is inherently paradoxical, and that if you examine any concept deeply enough, you will find that at its pinnacle it simply reverts to its opposite.
The self is real, because you are a physical being who eats and sleeps and has a name. The self is unreal, because it is entirely constructed from things that are not-you, genetics, experience, culture, the food you ate this morning. Both are completely true. Neither cancels the other.
Heaven at its extreme becomes Hell. Hell at its extreme becomes Heaven. Emptiness is also fullness. Samsara is also nirvana. The way that can be spoken is not the true way, and yet in speaking it, we make it so.
The discomfort one feels when confronted with genuine paradox is not a sign that something is wrong. It is the edge of Kenning, the place where the mind that wants to put everything in boxes meets something that will not fit. At that edge, you have two choices: expand, or turn away.
The whole of Tianmu's teaching can be said in one breath: Reality is paradox, and paradox is not a problem to be solved but the native language of existence. Learn to speak it.
The student, if she is brave, does not turn away. She sits at the edge where the labels fail. She holds the One and the Many in both hands and does not choose. And in that holding, that refusal to collapse into one pole or the other, something opens that was not open before.