What This Concept Is About
In the *Saṃdhinirmocana Sūtra* (《深密解脱经》, the *Sūtra Unraveling the Profound Mysteries*, translated by Bodhiruci of the Northern Wei), the 「第一義相」(paramārtha-lakṣaṇa, "the mark of ultimate truth") refers to the mark of the ultimate truth that transcends all worldly linguistic concepts and mental reckoning, is "neither one nor different" (不一不異) from the conditioned world, and is equal in one flavor and eternally unchanging in all places. It is the true suchness, the real nature of all dharmas, and it is also the "non-dual dharma" (不二法) and the "first realm beyond speech" (第一離言境) that practitioners personally realize through right-mindfulness practice.
To explain this concept thoroughly, one cannot stop at vague words like "inexpressible," but must place it within the entire skeleton of Yogācāra and the path of liberation, and carefully break it down into four core dimensions according to the sūtra's own exposition:
1. Beyond Speech and Thought, Transcending the Worldly
The sūtra first points out that the mark of ultimate truth is "the mark that surpasses the realm of all worldly perception-and-examination" (過諸一切世間覺觀境界之相).
In Bodhiruci's translation, all our daily reckoning, conceptual thinking, and logical analysis are collectively called 覺觀 ("perception and examination," i.e., vitarka-vicāra, "discursive thought"; rendered 尋伺 in Xuanzang's version). What we ordinarily take to be the "objective world" is in fact entirely built upon language, names, and perception-and-examination (conceptual thinking)—these constitute the worldly "mark of conventional truth" (世諦相) and the "realm of verbal expression" (言說境界), and they inevitably bring with them divergent standpoints and the "mark of disputation" (爭論相).
The mark of ultimate truth, by contrast, is the "realm beyond words" (無言境界) and "free from all language" (離諸語言). Ordinary people cannot imagine it because we have been habituated throughout the "long night" of ignorance to seeking pleasure within the frameworks of craving, discrimination, seeing-hearing-sensing-knowing, and "self and what belongs to self" (我與我所).
The sūtra offers several very vivid and rigorously structured analogies:
- The analogy of taste: A person who has only ever tasted bitterness and is habituated to it (one who has savored bitter flavors through the long night)—if you describe to him the sweetness of 石蜜 ("rock honey," sugarcane sugar) or 阿婆婆 (in the classical context, an extremely sweet delicacy/confection), he absolutely cannot imagine, measure, or believe it. - The analogy of desire and discrimination: A person scorched by the fire of craving cannot believe in the joy of being free from the five desires (五欲, pañca-kāma); a person habituated to constant abstraction and logical inference cannot believe in the joy of inner bodily stillness free from discrimination; a person attached to seeing-hearing-sensing-knowing cannot imagine the bliss of cessation that is free from seeing-hearing-sensing-knowing. - The analogy of region: A person habituated to the self-grasping of "this is mine, that is yours" is like someone who has never been to 北郁單越 (Uttarakuru, the northern continent of bliss and abundance, free from possessiveness)—he cannot imagine the pure happiness that is free from "grasping at self and grasping at what belongs to self."
Therefore, the mark of ultimate truth is by no means a "piece of knowledge" that can be worked out through reading, discussion, or debate—it is a "personally realized dharma" (身證法), verifiable only through personal practice and the utter eradication of delusive discrimination.
2. "Neither One nor Different" from the Conditioned Active Marks
Since the mark of ultimate truth is the ultimate truth, what exactly is its relationship to the ever-transforming, arising-and-ceasing "conditioned world" (有為行相, conditioned active marks) before our eyes? The *Saṃdhinirmocana Sūtra* gives a very rigorous dialectical conclusion: it cannot be said to be one, and cannot be said to be different—neither one nor different (非一非異).
- Why can it not be said to be "one" (not different)? If the mark of ultimate truth were completely identical with the conditioned active marks, serious logical and practical errors would follow: First, the utterly pure mark of ultimate truth would fall into defilement and arising-and-ceasing along with conditioned dharmas; Second, ordinary beings, upon seeing conditioned dharmas (for instance, seeing flowers bloom and wither), would already have seen the mark of ultimate truth—then ordinary beings would naturally be saints and would not need to cultivate at all or seek the supreme unsurpassed dharma; Third, there would be no process of transformation in practice from "this is defiled, this is pure." - Why can it not be said to be "different" (distinct)? If the mark of ultimate truth were completely separate from conditioned active marks, existing independently in another world, errors would likewise arise: First, all conditioned dharmas would lose their true suchness, becoming baseless illusory appearances; Second, practitioners could not, in the present body and mind (conditioned dharmas), break through delusion and realize truth through contemplation—defilement and purity would become two temporally unrelated things.
To clarify this relationship of "neither separate nor identical" (不離不即), the sūtra preserves four exquisite classical analogies:
1. The whiteness of the conch (珂白): The conch shell (珂) and its whiteness. You cannot say that whiteness is the conch (because other things are also white), but you absolutely cannot peel the whiteness off the conch either—apart from the conch, there is no such whiteness. 2. The yellowness of gold (金黃): Gold and its yellow color. 3. The fragrance of agarwood (沈水香味): Agarwood and its fragrance. 4. The sweetness of sugarcane (甘蔗甜味): Sugarcane and its sweetness.
Between the entity (the conditioned active marks) and its attribute/true nature (the mark of ultimate truth), the relationship is precisely this kind of "cannot be peeled apart, cannot be merged together"—neither one nor different.
3. One Flavor of All Dharmas and the Eternally Unchanging
Conditioned dharmas are infinitely various (mountains and rivers, plants and trees, joy and anger are all different), but the mark of ultimate truth possesses the quality of "one flavor, equal flavor" (一味等味).
The sūtra uses space (虛空) as its analogy: whether the container is square or round, pure or filthy, the "space" inside the container is equal and undifferentiated in all places. The mark of ultimate truth is likewise—it is the true suchness dharma-nature underlying all dharmas.
This "true suchness, ultimate truth, dharma-selflessness" (真如第一義諦法無我) is not produced by causes and conditions, nor is it a conditioned dharma of arising and ceasing. Whether or not a Buddha appears in the world, whether or not anyone realizes it, it is the objective reality of "dharma-nature ever-abiding, dharma-essence ever-abiding, dharma-realm ever-abiding" (法性常住、法體常住、法界常住).
4. Its Position in the Three Marks, the Three Marks of No Self-Existence, and the Definitive-Meaning Teaching
In the full landscape of Yogācāra, the mark of ultimate truth has an extremely clear position:
- In the "three marks" (三相): it corresponds to the imagined nature (遍計所執, translated here as "the mark of delusive discrimination," 虛妄分別相), the dependent nature (依他起, translated here as "the mark of other-powered causes and conditions," 他力因緣相), and the perfected nature (圓成實, which is precisely the "mark of ultimate truth," 第一義相). - The sūtra uses eye disease as its analogy: the hallucinations caused by eye disease (the eye film, 眼瞖) are the mark of delusive discrimination; the hair-wheels seen in the air because of the eye disease are the mark of dependent arising; and the clear, limpid vision seen when "the eye is pure and free of turbidity" (眼淨無濁) is the mark of ultimate truth. - In the "three marks of no self-existence" (三無自體相): it corresponds to the "mark of no self-existence of the ultimate truth" (第一義諦無自體相). It is the realm of "dharma-selflessness" (法無我) manifested through pure contemplation of all dharmas, originally and intrinsically nirvāṇa. - In the "definitive-meaning teaching" (了義教, nītārtha): the bodhisattva who has accomplished the ultimate truth compares the definitive-meaning teaching of the mark of ultimate truth to: - The herb Piśubhā (毘舒婆藥草): added to all medicines, it produces miraculous efficacy; - Mature ghee (熟酥): extracted from food and drink, it is the supreme flavor; - Space (虛空): providing unobstructed room for all activities.
A Walkthrough in Daily Life
So that the "mark of ultimate truth" does not become an abstract noun, we can walk through it using the most familiar scenario of contemporary life—the psychological process of scrolling through your phone at work and receiving negative feedback in a work group chat—strictly following the structure of the classical definitions:
Scenario Walkthrough: A WeChat Notification on a Late Work Night
At 11 p.m., you have just gotten ready for bed when your phone rings. Your manager posts a message in the work group: "This proposal's logic does not hold up at all. Redo it first thing tomorrow morning."
1. The rise of the mark of delusive discrimination (the imagined nature): You read the message and your mind instantly explodes: "He is targeting me!" "Is he trying to force me to quit?" "I have wasted an entire month—I am a failure." - Classical mapping: This is the "mark of delusive discrimination" (the eye film). You have plastered countless labels of self-defense, persecution fantasy, and emotional reactivity onto the written symbols (perception-and-examination / names / verbal marks). The place where people most commonly mis-map is in thinking that the "sense of frustration" before them is a real, objectively existing entity, when in fact it is entirely a web of concepts woven into empty theorizing (戲論).
2. Restoring the mark of other-powered causes and conditions (the dependent nature): If you calm down a little and use reason to sort out the matter: the optoelectronic signals on the phone screen, the manager's anxious mood arising from stress, certain data errors that do exist in the proposal, your own fatigued mental state—all these conditions (causes and conditions) interweave to bring about the phenomenon of "seeing this line of text and feeling your heart rate spike." - Classical mapping: This is the "mark of other-powered causes and conditions" (the hair-wheel seen due to the eye disease). All phenomena arise dependently upon various conditions; there is no independently self-existing entity.
3. Directly realizing the mark of ultimate truth (the perfected nature): If at this very moment you suddenly withdraw from attachment to labels (free from perception-and-examination), neither treating "the manager's words" as a negation of "me" nor denying the anxiety of the present moment, but directly observing: The anxious thought arises, and it also ceases; the light of the screen is merely a physical phenomenon; the "me" that feels injured is, in essence, nothing but an illusion patched together from a series of thoughts (dharma-selflessness). At this instant, your mind-essence is intrinsically still, undefiled, and has not been diminished in the slightest. - Classical mapping: This is precisely the "mark of ultimate truth" (the eye pure and free of turbidity). The true suchness dharma-nature has not departed from this WeChat message (not different), but it is absolutely not the emotional turmoil brought by the content of the message itself (not one). It is like the sweetness in sugarcane, the whiteness on the conch—it runs through this entire experience, yet is originally pure.
Where people most commonly mis-map:
- Misconception one (誤區一): Thinking that the mark of ultimate truth means "jumping out of this world and going to a paradise where there are no work messages and no afflictions whatsoever." (Wrong! This severs the conditioned from the unconditioned, committing the error of "declaring difference.") - Misconception two (誤區二): Thinking that the mark of ultimate truth means "being scolded is also a good thing; being scolded equals purity." (Wrong! This confuses defilement with purity, committing the error of "declaring oneness.")
Why Contemporary People Need It
Contemporary life is an era submerged in algorithms, labels, and extreme conceptualization (perception-and-examination).
Every day we live in a cage of concepts: KPIs, asset tiers, age anxiety, social personas—all of these are what the sūtra calls "conventional names" (世諦名字) and the "realm of verbal expression" (言說境界). We madly roll around in concepts, producing endless "marks of disputation" (爭論相)—online mutual abuse, workplace involution, right-and-wrong tearing in intimate relationships.
A parallel with contemporary experience (such as AI and digital life):
It is like being immersed in an extraordinarily realistic VR game. The damage taken, the leveling up, the gold coins in the game (conditioned active marks) send our emotions into violent swings.
- The contemporary way of trying to solve suffering is often to seek within the game itself: change to better equipment, defeat that NPC (fussing about within worldly dharmas). - The "mark of ultimate truth," by contrast, reminds you: notice the underlying code and the screen itself that support the entire game's operation.
Here we can borrow the cutting-edge brain science of "Predictive Processing" (預測編碼理論) as a comparison: modern neuroscience has found that the human brain does not passively receive external signals, but continuously imposes "prediction models" (mental filling-in) on the outside world based on past experience. What we think we see as "reality" is largely a "hallucination" predicted by the brain (very close to "delusive discrimination").
- The limit of science: Brain science can tell you how the brain "manufactures hallucinations" through neural networks, but it cannot provide a path of liberation that enables the mind to completely transcend hallucination and attain ultimate freedom. - The wisdom of Buddhism: The mark of ultimate truth directly points to that "dharma-nature ever-abiding" which is not shaken by hallucination. It tells you: you do not need to destroy the conditioned world (you do not need to smash your phone or flee society); you only need, in each conditioned moment, to see through concepts (free from perception-and-examination) and recognize the original equal one-flavor of all dharmas.
This gives contemporary people a highly constructive "dual-life capacity" (雙重生活能力): On the conventional level, you can continue to diligently work on proposals and manage relationships (going along with conventional truth, skillfully using the dependent nature); On the spiritual foundation, you possess the grounding of the mark of ultimate truth—you know that all this arising-and-ceasing, praise and blame, is like foam and phantom images, and your inner core forever abides in the limpid purity of "one flavor, equal flavor." You can no longer be completely crushed by any worldly gain or loss.
Common Misreadings and Clarifications
Misreading One: "Since the mark of ultimate truth is 'inexpressible,' we should all just stop talking—even discussing Buddhism is frivolous theorizing."
Clarification: This is a classic fall into nihilism (the view of annihilation, 斷滅見).
The *Saṃdhinirmocana Sūtra* specifically emphasizes that although the mark of ultimate truth is the "realm beyond words," the sages, in order to guide sentient beings into this wordless dharma, must use language to reveal it.
As the sūtra illustrates with the analogy of "illusion" (幻術): a wise person sees the magician conjure elephants and horses, knows that the elephants and horses are not real (does not take them as actual), yet he still uses these verbal symbols of "elephant" and "horse" to point you toward the truth. Language is the finger pointing at the moon—the finger is not the moon, but only by following the finger can you see the moon.
Misreading Two: "The mark of ultimate truth is the 'first cause' or 'creator' of all things."
Clarification: Wrong. Western philosophy and theology often seek an initial "first cause" (such as God, or the singularity before the Big Bang). But the mark of ultimate truth is "not born of causes and conditions, not conditioned" (非因緣生，非是有為). It is not an entity that creates all things, but rather the true suchness nature (dharma-selflessness) of all things themselves in the present moment. Its relationship to all things is neither one nor different—not a temporal cause-and-effect relationship of "creator and created."
Misreading Three: "As long as I think about nothing (non-thinking / cutting off all thoughts), I am experiencing the mark of ultimate truth."
Clarification: Treating "not thinking" as the mark of ultimate truth is a serious misunderstanding.
What the sūtra means by "free from all perception-and-examination" (離諸覺觀) is departing from deluded attachment to conceptual labels, not becoming an unconscious state like a stone or a piece of wood. If "non-thinking" were the mark of ultimate truth, then ordinary beings in deep sleep or under anesthesia would all be awakened ones.
The true mark of ultimate truth is a "personally realized dharma" (身證法)—it carries an extremely clear, pure wisdom (the mark of pure contemplation, 清淨觀相), and within the arising-and-ceasing of all things, it illuminates the dharma-nature that neither arises nor ceases.
Summary: The Ultimate Position of the Mark of Ultimate Truth in the Path of Liberation
The mark of ultimate truth is not a doctrine floating in the air to be worshipped; it is the ultimate orientation and foundational ground of the entire path of liberation.
It tells the practitioner: affliction and bodhi, the world and nirvāṇa, have never been two separate worlds. Practice is not about manufacturing a "purity" out of thin air, but about recognizing, through right-mindfulness contemplation in each conditioned moment, the mark of ultimate truth that has never been defiled, is neither one nor different, and is equal and ever-abiding. Just as mature ghee is placed in food and drink, and the herb among all medicines—once the mark of ultimate truth is recognized, the whole of worldly life is thereby transformed into a site of liberation (道場).