What this concept is saying
Èryí (二儀, “the Two Principles”) is an old Chinese expression for the paired cosmic principles of Heaven and Earth (天地) or yin and yang (陰陽). In ordinary cosmological language, it can name the two great poles through which the world becomes differentiated and ordered. In the Chan usage preserved in the *Extensive Record of Chan Master Hongzhi* (*Hóngzhì Chánshī Guǎnglù*, 《宏智禪師廣錄》, T2001), however, the decisive point is not that reality consists of two opposing forces. Hongzhi turns attention toward what is present before—and within—their division.
His phrases are exact and mutually illuminating:
- “the numinous awareness before yin and yang were divided” (「陰陽未判之靈」); - “the uncarved simplicity before primordial chaos” (「混沌已前之樸」); - “the Two Principles are naturally one body” (「二儀自然一體」); - “the Two Principles share one root; the myriad things have one source” (「二儀同根，萬物一源」).
These expressions describe four related dimensions of the teaching: the undivided origin, differentiation into paired principles, the appearance of the myriad phenomena, and unobstructed functioning amid those phenomena. They should not be flattened into the vague slogan “everything is one.”
First comes the originally undivided. “Before yin and yang were divided” does not merely indicate a remote moment in a Chinese creation story. In Chan, it points contemplatively to experience before the discriminating mind has hardened it into opposed camps: self and other, gain and loss, attractive and repulsive, sacred and ordinary. “Before” is therefore not only chronological. It is available in the very arising of the present moment—before an event is seized, named, judged, and woven into “my” story.
Hongzhi calls this undivided dimension both líng (靈, numinous or vividly aware) and pǔ (樸, uncarved simplicity). It is not a blank, unconscious mass. Nor is it the intellectual idea that opposites are secretly identical. It is simple without being inert and aware without dividing experience into a watcher over here and a watched object over there.
Second comes differentiation. Heaven and Earth remain Heaven and Earth; yin and yang have distinct functions. Chan does not abolish difference. Day is not night, care is not cruelty, and wisdom is not confusion. “Two Principles” therefore preserves the reality of distinction, while “naturally one body” prevents distinction from being mistaken for absolute separation.
This is the heart of the expression: not two does not mean featureless sameness; two does not mean independent opposition. The two are distinguishable in function but not separable in their ground. Like the front and back of one hand, they cannot be collapsed into one surface, yet neither can exist as an independent hand.
Third comes the manifestation of the myriad phenomena. Hongzhi calls the Two Principles “the gate of the Two Principles, the root of the myriad phenomena” (「二儀之門，萬象之根」). “Gate” emphasizes emergence: differentiation is the passage through which the concrete world appears. “Root” emphasizes dependence: the many do not stand apart from their source. Thus Hongzhi can also say that “the myriad phenomena have no other form” (「明知萬像不他形」). Mountains, voices, bodies, traffic lights, grief, weather, and thought are not alien debris obscuring an otherwise pure unity. They are the very display of reality in differentiation.
Yet this root must not be turned into a hidden cosmic object. Hongzhi immediately frustrates that move: “being and nonbeing are difficult to discuss; blue and white leave no trace” (「有無難議，青白不痕」). The source cannot adequately be classified as an existent thing, a nonexistent void, or an object possessing determinate qualities. Language can indicate it, but any label that seems to capture it has already placed it on one side of a distinction.
Fourth comes mutual circulation and functioning. Hongzhi says, “the Two Principles and the myriad phenomena mutually circulate” (「二儀萬像兮相與流通」), followed by “through the ten directions and the three times, they naturally emerge on equal ground” (「十方三世兮自然平出」). Source and manifestation are not two floors of the universe, with an absolute realm upstairs and ordinary life downstairs. The undivided is present as differentiation; differentiation continually expresses the undivided.
This is why Hongzhi can speak of “wondrous emptiness throughout the three times, completely encompassing the Two Principles” (「妙空三世，圓包二儀」). Wondrous emptiness (妙空) is not a vacant space surrounding Heaven and Earth. “Empty” indicates that neither pole nor any phenomenon possesses a fixed, self-sufficient nature; “wondrous” prevents emptiness from being mistaken for dead nothingness. Precisely because things are not sealed in independent essences, they can arise together, affect one another, and function.
The concept’s place on the path of liberation is therefore practical. Bondage begins when useful distinctions become absolute divisions: “I am this kind of person”; “you are the enemy”; “success will complete me”; “this pain must not exist.” Liberation does not require erasing distinctions. It requires seeing that neither member of a pair stands by itself, then responding within the differentiated world without being imprisoned by it.
Hongzhi expresses this as being “not enclosed by the Three Realms” yet operating within “the range of the Two Principles” (「非三界之籠絡」「是二儀之範圍」), alongside “coming without coming” and “dwelling without dwelling” (「不來而來」「無住而住」). Here the Three Realms (三界) are the entire conditioned field of cyclic existence, conventionally described as the desire, form, and formless realms. To escape their enclosure does not mean fleeing Heaven, Earth, bodies, relationships, or causality. It means no longer making a fixed dwelling out of any experience while remaining fully able to act within experience.
Thus the path moves through three inseparable insights:
1. Before fixation, experience is not divided into a sovereign self confronting an alien world. 2. Distinctions nevertheless arise and must be discerned accurately. 3. Wise conduct functions through distinctions without clinging to either side.
That is considerably subtler than choosing unity over duality. Choosing “unity” against “duality” merely creates a new duality.
A walk-through in everyday life
Imagine an argument between partners after one of them has again answered work messages during dinner.
The phone lights up. There is a sound, a tightening in the chest, a facial expression, and a change in the room’s atmosphere. At this first instant, the event has not yet become the complete narrative “You never care about me.” This immediate, vivid field illustrates—not proves or exhaustively defines—what Hongzhi indicates with “the numinous awareness before yin and yang were divided.” The point is not that sensory experience literally precedes all mental processing in a scientifically measurable sequence. The phrase is a contemplative instruction: notice the moment before conceptual fixation takes possession of what is happening.
Differentiation then appears. There are genuinely two people, different needs, an illuminated phone, interrupted attention, hurt, responsibility, and a history of previous dinners. This is the level of the Two Principles: relational poles and distinctions have arisen. It would be a serious mistake to map “nonduality” onto the claim that no disagreement exists, that both partners are equally responsible, or that boundaries do not matter. Heaven is not Earth; yin is not yang. A promise kept differs from a promise broken.
Next, the mind converts functional distinction into absolute separation: “I am the neglected one; you are the selfish one.” Each person now appears to possess a fixed identity independent of conditions. But the anger depends on fatigue, expectations, workplace pressure, earlier injuries, affection, fear, bodily arousal, and the wish to be valued. The phone use also depends on habits, incentives, colleagues, anxiety, and the design of attention-capturing software. Neither side exists alone. Here “the Two Principles share one root; the myriad things have one source” means that the opposed positions arise within one interdependent situation. It does not mean that every action is morally equivalent.
Seeing the common situation changes the available response. One partner might say: “When the phone came out again, I felt pushed aside. I need us to protect this half-hour.” The other might put the device away, acknowledge the broken agreement, and explain the work emergency without using it to erase the hurt. Distinction remains: one speaks, another listens; one caused a particular injury, another received it; a boundary is established. Yet the exchange is no longer organized around two fortified selves.
This is mutual circulation in lived form. Feeling becomes speech; speech becomes hearing; hearing alters feeling; understanding becomes a concrete agreement. The undivided source is not somewhere behind the conversation. It functions as the conversation’s openness—the fact that neither person nor moment is fixed, and therefore a new response is possible.
The most common mapping error is to identify one participant with yin and the other with yang, perhaps along gender stereotypes. That is not what Hongzhi’s usage requires. Yin and yang name relational modes, not permanent personal essences. In a single conversation, receptivity and initiative, silence and speech, firmness and yielding can alternate in either person.
A second error is to assign the calm moment to “oneness” and the argument to “duality.” Hongzhi’s “myriad phenomena have no other form” blocks this escape. The ringing phone, anger, apology, and boundary all arise within the same field. Practice is not a retreat from the many into a privately enjoyed One. It is the capacity to meet the many without producing absolute separation.
Consider the same movement while commuting. A crowded carriage immediately differentiates into “my space” and “their bodies,” delay and destination, irritation and relief. Those distinctions are needed: you must know which stop to take and whether someone needs a seat. Trouble begins when “the passenger blocking the door” becomes nothing but an obstacle to “me.” Seeing common conditions—crowding, fatigue, limited space—does not require approving inconsiderate behavior. It allows a clear request without the extra construction of an enemy.
Or while scrolling a personalized feed: the algorithm sorts the world into relevant and irrelevant, agreeable and offensive, likely engagement and likely indifference. These classifications can amplify the mind’s tendency to treat relational judgments as properties inherent in things: “This person simply is contemptible.” Remembering the Two Principles means noticing both the differentiation and the wider field that generates it—platform incentives, prior clicks, social identity, emotional state, and selective presentation. This analogy has limits: algorithms are engineered systems, while Hongzhi is speaking about liberation and the nature of experience. Computer science neither proves nor disproves the Chan teaching. It simply gives contemporary readers a vivid example of how unnoticed sorting can harden into an apparently self-evident world.
Why contemporary people need it
Contemporary life is highly skilled at producing pairs and poor at teaching us how to inhabit them: online and offline, productive and unproductive, winner and loser, progressive and reactionary, human and machine, work and life. Classification itself is not the enemy. Without distinctions, there is no medicine, ethics, engineering, or responsible judgment. The suffering comes from forgetting that classifications are conditioned, relational, and purpose-bound.
The teaching of the Two Principles offers a discipline of non-absolutization. It asks us to discern without reifying, to oppose harm without manufacturing an intrinsically evil other, and to affirm intimacy without erasing difference. This has consequences at several levels.
Psychologically, it loosens identity. A person may have failed without becoming “a failure.” Anxiety may be present without constituting an unchanging anxious self. The distinction between wholesome and unwholesome responses remains indispensable, but neither is treated as an eternal substance.
Relationally, it makes accountability more intelligent. “We are one” cannot excuse abuse or dissolve consent. Precisely because self and other arise relationally, one person’s conduct matters profoundly to the other. Nonseparation intensifies responsibility; it does not cancel it.
Socially, it provides a way to resist polarization without falling into false equivalence. Two political claims may not be equally truthful or harmful. Seeing their conditioned arising does not prevent evidence-based judgment. It prevents judgment from becoming hatred built upon the fantasy that one side exists in moral isolation from the shared world that produced both.
Contemplatively, it corrects the wish to find a special spiritual state outside ordinary life. Hongzhi’s language of “range,” “encompassing,” and “circulation” places realization amid Heaven and Earth and the myriad phenomena. The practitioner does not graduate from difference. One learns not to dwell in it.
This is where the concept belongs in the whole path of liberation. Ethical discipline steadies conduct so that greed, hostility, and confusion do not continually reinforce a defended self. Meditative composure makes it possible to observe differentiation before reflexive grasping takes over. Wisdom sees that paired terms and the self who clings to them arise dependently and lack independent essence. Compassion then becomes natural functioning within distinction: because self and other are not sealed off, another’s suffering is not truly irrelevant; because they are not simply identical, help must fit the other person’s actual circumstances.
The realization of “one body” is therefore tested by conduct. If it produces vagueness, passivity, grandiosity, or indifference to consequences, it has become an idea. If it permits precise perception, less defensive reaction, firmer compassion, and action without fixation, it has begun to function as liberation.
Common misreadings and clarifications
“The Two Principles means a cosmic battle between two independent powers.” Not in Hongzhi’s presentation. Although the term names Heaven and Earth or yin and yang, the record repeatedly emphasizes “naturally one body,” “one root,” and “one source.” Difference is real as function, not as independent self-existence.
“It simply means yin and yang after they have separated.” That is too narrow. Hongzhi deliberately points to “the numinous awareness before yin and yang were divided.” His concern includes the undivided source, differentiation, the manifestation of the myriad phenomena, and their unobstructed circulation.
“Before division” describes only the chronological beginning of the universe. The expression draws on cosmological language, but Chan uses it as a pointer to present realization. Searching for an event in the remote past misses its practical force: can one encounter this moment before grasping divides it into a fixed self and fixed objects?
“One body” means all differences are unreal or unimportant. No. If difference vanished, there could be no “Two Principles,” no myriad phenomena, and no responsive activity. Conventional distinctions—including truth and falsehood, consent and coercion, beneficial and harmful action—remain necessary. Their emptiness means that they are conditioned and relational, not that they are useless.
“One source” is a permanent metaphysical substance behind the world.” Hongzhi’s “being and nonbeing are difficult to discuss; blue and white leave no trace” warns against turning the source into a hidden thing. The text points beyond classification as either a substantial entity or sheer nothingness. To name it a cosmic Self would impose precisely the fixed determination the language refuses.
“Primordial chaos” means confusion or unconscious blankness. Here “the uncarved simplicity before primordial chaos” is paired with numinous awareness. It signifies uncontrived wholeness, not cognitive muddle, coma, or suppression of thought. A dull meditation state is not liberation merely because distinctions have temporarily faded.
“Nonduality means staying neutral.” Nonduality is not indecision. A liberated response may be gentle or fierce, receptive or decisive. What drops away is fixation and self-centered dwelling, not discriminating wisdom. One can stop harm without converting the person causing it into an eternally separate essence.
“The myriad phenomena are lower appearances, while the One is the higher truth.” Hongzhi says that the Two Principles and myriad phenomena “mutually circulate” and that the phenomena have “no other form.” This denies a crude two-story model. The source is not elsewhere; it is known in the empty, interdependent arising of concrete things.
“The ‘range of the Two Principles’ is another enclosure.” In context, “range” is paired with being outside the enclosure of the Three Realms and with “dwelling without dwelling.” It means functioning throughout the entire differentiated field, not confinement within a metaphysical cage.
“Chan is borrowing Chinese cosmology, so the Two Principles must be a standard Indian Buddhist doctrine.” The expression is distinctly Chinese in vocabulary and cultural background. Hongzhi employs that inherited language to articulate Chan realization. It should not be retroactively presented as though “二儀” were a standard Sanskrit doctrinal category or a universal Buddhist technical term found everywhere in the canon.
The mature understanding can be stated simply: before division, there is no fixed opposition; after division, distinctions function clearly; throughout both, nothing stands alone. To realize the Two Principles is not to escape the world’s pairs, nor to be deceived by them. It is to move through Heaven and Earth without making a permanent home on either side.