来书云：「元神、元气、元精必各有寄藏发生之处；又有真阴之精，真阳之气。」云云。
夫良知，一也。以其妙用而言，谓之神；以其流行而言，谓之气；以其凝聚而言，谓之精；安可以形象方所求哉？真阴之精，即真阳之气之母，真阳之气，即真阴之精之父；阴根阳，阳根阴，亦非有二也。苟吾良知之说明，即凡若此类，皆可以不言而喻；不然，则如来书所云「三关」、「七返」、「九还」之属，尚有无穷可疑者也。
来信说：「元神、元气、元精必定各有寄藏发生之处；又有真阴之精、真阳之气」云云。
良知只是一个。就其妙用而言叫作神，就其流行而言叫作气，就其凝聚而言叫作精，怎么可以从形象方位去求呢？真阴之精，就是真阳之气的母；真阳之气，就是真阴之精的父。阴根于阳，阳根于阴，也不是两个。假如我的良知之说明白了，那么凡此类问题都可以不言而喻；不然，就像来信所说的「三关」「七返」「九还」之类，还有无穷可疑的呢。
Your letter says: 'Primal spirit, primal breath, primal essence must each have its lodging and springing place; and there are the essence of true yin and the breath of true yang,' and so on.
Innate knowledge is one. Of its wondrous working it is called spirit; of its flowing forth, breath; of its congealing, essence — how seek it by form and place? The essence of true yin is mother of the breath of true yang; the breath of true yang, father of the essence of true yin: yin rooted in yang, yang in yin — not two either. Let my doctrine of innate knowledge once be clear, and all such questions answer themselves; otherwise, with your three passes, seven returns and nine turnings, the doubts would indeed be endless.