The Relative Identity of All Objects: Tiantai Buddhism Meets Analytic Metaphysics

2.1. The Interconnectedness of All Objects

Zhiyi generalizes his thesis of interconnectedness from a well-known Tiantai tenet called “three thousand dharmas in one single thought.” In Buddhism, dharma 法 is a polysemous term whose meanings may vary drastically in different contexts.⁴ Here, dharma is understood as “object” or “thing” in the most general and all-encompassing sense. Under this understanding, dharmas are thought to have characteristics that separate them from each other. The defining characteristics of dharmas allow us to conceptualize, verbalize, and categorize them.

Zhiyi calculates three thousand dharmas from three pre-existing Buddhist ways of categorizing objects: the ten dharma realms 十界, the ten suchlikes 十如是, and three categories in which the world is divided 三種世間. First, the ten dharma realms correspond to the ten kinds of sentient beings in Mahāyāna Buddhism:⁵ Buddha, bodhisattva, pratyekabuddha,⁶ śrāvaka,⁷ celestial being, human, asura,⁸ animal, hungry ghost, and hell being.⁹ Different kinds of sentient beings have different experiences. For example, hungry ghosts eat feces; they drink urine, pus, and blood. No matter how much they eat and drink, they are always hungry and thirsty. What a hungry ghost perceives differs significantly from what a human being perceives. This is the case even if a hungry ghost and a human share the same food or drink. While a human might taste delicious orange juice, a hungry ghost would taste the same drink as unpalatable blood.

Second, the ten suchlikes are characteristics of objects, including their appearance, nature, essence, power, activity, cause, condition, effect, recompense, and ultimate equality of beginning and end.¹⁰ The literal meaning of suchlike implies that it is about how objects truly are. The ten suchlikes cover all sorts of features of an object, including what it appears to be, its nature and defining characteristics, its potentiality, and its relations to other objects.

Third, the world is divided into three categories: the world of sentient beings 眾生世間, the world of the five skandhas 五陰世間, and the world of lands where sentient beings reside 國土世間. Sentient beings are composed of the five skandhas, or the five aggregates, which include physical body, feelings of pleasure, pain and indifference, perception, volitional formation, and consciousness.¹¹ These aggregates collectively constitute the entirety of a sentient being. Although different sentient beings do not typically live together—for example, some hell beings dwell in hot iron, while Buddhas live in pure lands—bodhisattvas and human beings can live together.

According to the standard interpretation of Zhiyi’s view,¹² all ten dharma realms are present in one single thought. Moreover, in each dharma realm, there are all ten dharma realms, all ten suchlikes, and all three categories in which the world is divided. So, in total, there are three thousand dharmas in one single thought.¹³ While the number three thousand seems definitive, it is employed metaphorically rather than as a literal count. The ten dharma realms, the ten suchlikes, and the three categories in which the world is divided were pre-established Buddhist categories in Zhiyi’s time. They exemplify different ways of categorizing objects. By appealing to various categories, Zhiyi makes the point that the scope of his thesis is supremely vast. It encompasses all sorts of things, including physical and mental objects, all their characteristics, and the locations they occupy. Furthermore, one single thought, which falls under the consciousness skandha, is a dharma. In Zhiyi’s view, all dharmas are not only in any single thought but also in any single dharma. The relationship between a single thought and three thousand dharmas illustrates a more overarching connection between any single dharma and all dharmas.¹⁴ From “three thousand dharmas in one single thought,” Zhiyi develops the most extensive thesis of interconnectedness, according to which a total relation connects everything to everything (i.e., ∃R∀x∀y(Rxy)). This thesis of interconnectedness surpasses weaker forms of interconnectedness, such as everything stands in a single relation—regardless of its place in the relation—to everything (i.e., ∃R∀x∀y(Rxy∨Ryx)), everything bears a single relation to something (i.e., ∃R∀x∃y(Rxy)), and everything is connected to everything by some relation (i.e., ∀x∀y∃R(Rxy)).

In what sense are three thousand dharmas in one single thought? Or, more generally, what relation connects everything to everything? Zhiyi’s answer is complicated and obscure. Zhiyi uses the Chinese verb ju 具, conveying the meaning of having and possessing, to characterize the relation between one single thought and three thousand dharmas:

One single thought ju the ten dharma realms. Moreover, one dharma realm ju the ten dharma realms, so one dharma realm ju one hundred dharma realms. One dharma realm ju thirty types of worlds. One hundred dharma realms hence ju three thousand types of worlds. These three thousand exist [at/in] one single thought. If there is no thought, that is the end of the matter. Once there is even a single thought, it ju the three thousand.¹⁵

Nonetheless, Zhiyi blocks two potential misunderstandings of his view:

But it cannot be said that the arising of one single thought is before, and that the arising of all dharmas is after. Nor can it be said that the arising of all dharmas is before, and that the arising of one single thought is after. For example, it is like a thing that changes through eight aspects [of arising, abiding, changing, and perishing]. If a thing arose before its eight aspects, it would not be changed. If a thing arose after its eight aspects, it would not be changed. It can be neither before nor after. It is just that a thing is viewed as its changing aspects and that its changing aspects are viewed as a thing. Thoughts are just like this. If all dharmas arise from one single thought, it is vertical. If one single thought contains all dharmas, it is horizontal. It cannot be vertical. Nor can it be horizontal.¹⁶

Firstly, one single thought does not arise before all dharmas; hence the existence of one single thought does not causally generate the existence of all dharmas. Secondly, one single thought does not contain all dharmas as its mereological parts. After all, one single thought is one of the three thousand. Additionally, it might be tempting to misinterpret “one single thought ju three thousand dharmas” as one single thought is ontologically prior to and grounds the existence of all dharmas.¹⁷ Nonetheless, in Zhiyi’s view, the relation between one single thought and all dharmas is shared by any two dharmas. Hence, a question arises: How can any two dharmas be prior to each other without violating the asymmetry of the priority relation?

Zhiyi seems to identify one single thought—and more generally, one dharma—with all dharmas when he uses the verb shi 是 to describe the relation between one single thought and all dharmas:

It is just that one single thought shi (is) all dharmas. All dharmas shi (are) one single thought.¹⁸

The Chinese verb shi operates similarly to the English copula be, connecting the subject of a clause to the following words that identify or describe it. When shi is placed before a noun phrase, it conveys the connotation of equivalence. Hence, it is tempting to interpret Zhiyi as saying that the relation between one dharma and all dharmas is the numerical identity relation that a thing bears to itself.¹⁹ Nonetheless, this straightforward reading is in tension with what Zhiyi says about the ten dharma realms:

Again, each of the ten dharma [realms] has its own causes and own results that are not mixed or confused with the others; therefore, they are called “ten dharma realms.”²⁰

Zhiyi appeals to the qualitative differences between the ten dharma realms to explain their numerical multiplicity. Given that three thousand dharmas are derived from the ten dharma realms, three thousand dharmas are numerically distinct and should not be mixed or confused with each other. What is worse, Zhiyi seems to contradict himself by claiming:

[One single thought and all dharmas are] neither identical nor distinct.²¹

Not only does this claim appear to be self-contradictory, but it also seems to negate both the claim that one dharma is all dharmas and the claim about the multiplicity of the ten dharma realms.

In sum, Zhiyi describes the interrelation between one dharma and all dharmas as follows:

The interrelation between all dharmas appears to be both mysterious and paradoxical. We encounter issues if we interpret (4) as meaning that one dharma is numerically identical with all dharmas. Primarily, the numerical identity between one dharma and all dharmas is difficult to comprehend. As Zhiyi acknowledges, how can all these objects be numerically identical while possessing different features? Moreover, each pair of (4), (5), and (6) are inconsistent.

Even if we do not interpret (4) as meaning that one dharma is numerically identical with all dharmas, challenges remain. It is mysterious what relation can satisfy (1) and (4). In other words, in what sense does one dharma have all dharmas? In what sense is one dharma all dharmas? Furthermore, the inconsistency between (5) and (6) persists.

Zhiyi’s discussion of the thesis of interconnectedness is a crucial component of his exploration of “the realm of the inconceivable 不可思議境.” This realm, as its Chinese name implies, cannot be thought of and discussed. Immediately after describing the interrelation between one dharma and all dharmas, Zhiyi remarks:

It is mysterious, subtle, and extremely profound. It is neither what can be conceptualized nor what can be verbalized. This is why it is called “the realm of the inconceivable.”²²

It is tempting to think that Zhiyi resorts to mysticism at this point. If the interrelation between all dharmas is beyond conceptualization and verbalization, then any attempt to specify and grasp the interrelation through conceptual understanding is doomed to fail and may lead to paradoxical claims. Nonetheless, the mysticist interpretation leads to a disappointing view. Not only will the interrelation between one dharma and all dharmas always remain mysterious, but its ineffability cancels out Zhiyi’s assertions about the interrelation. On what grounds is Zhiyi allowed to repeatedly speak of “one dharma is all dharmas” if the interrelation between all dharmas is beyond speech? Hence, it is worthwhile exploring an alternative interpretation of the remark that can resolve the tension between the realm of the inconceivable and Zhiyi’s conceptual and verbal attempt to explain and teach the interrelationship between all dharmas. This task is at least prima facie possible based on two observations. First, Zhiyi’s texts do not specify what is mysterious. If something else is mysterious, the interrelation between all dharmas can still be articulated and explained. Second, Zhiyi claims that dharmas—that are thought of and discussed—go hand in hand with the realm of the inconceivable:

Traversing every [dharma], it is all [encompassed] by the realm of the inconceivable.²³

If the realm of the inconceivable is compatible (or even integrated) with thinkable and discussable dharmas, there is a hope that the same realm does not preclude a thinkable and discussable interrelation between dharmas. To fully understand Zhiyi’s puzzling interrelation between all dharmas and see whether it can be intelligible, we need to see how Zhiyi develops his thesis of interconnectedness in accordance with his analysis of the dependent nature of all dharmas.

2.2. The Threefold Truth

Zhiyi’s metaphysics—and Chinese Buddhism in general—was shaped by the teachings of Indian Buddhist Nāgārjuna (ca. 150–250), the most prominent Buddhist philosopher after the historical Buddha. In particular, Zhiyi’s account of the threefold truth 三諦—the truth of conventionality, the truth of emptiness, and the truth of the middle—is primarily inspired by Kumārajīva’s Chinese translation of verse 18 in chapter 24 of Nāgārjuna’s Mūlamadhyamakakārikā:²⁴

All dharmas arise through causes and conditions.
This, I explain as emptiness.
And it is a conventional designation.
And it is the middle way.

Zhiyi interprets the verse as saying that all objects are dependently originated and analyzes the dependent nature of all dharmas in terms of emptiness, conventionality, and the middle way.²⁵ In a nutshell, emptiness, the thesis that all things have no intrinsic nature, emphasizes the absence of independent existence and objectivity in all objects, whereas conventionality portrays all objects as provisional constructs created and posited by us for practical purposes. Furthermore, Zhiyi stresses the harmony and balance between emptiness and conventionality within the middle way. For him, emptiness, conventionality, and the middle way are “perfectly integrated; one-in-three and three-in-one.”²⁶

To grasp the rich meanings of conventionality and emptiness as used by Zhiyi, it is crucial to trace the development of these notions prior to Zhiyi. The conventional-ultimate distinction prevails in Abhidharma Buddhism, the Buddhist phase between Early Buddhism and Mahayana Buddhism.²⁷

Ultimate truth is independent of us and characterizes objective reality.

Conventional truth is produced by our collective conceptual and linguistic activity for its usability in various human practices.

The two kinds of truth correspond to two kinds of existents.

Primary existents have intrinsic nature (Sanskrit: svabhāva²⁸) in the sense that they are irreducible, mind-independent existents.

Conventional existents arise from our conceptual and linguistic activity. We construct and accept them for their uses in our practice.

The two-tier framework of Abhidharma metaphysics is revolutionized by Nāgārjuna’s thesis of emptiness (Sanskrit: sūnyatā) in two significant ways. Firstly, according to the thesis of emptiness, all things are empty of intrinsic nature in the sense that they lack independent existence and objectivity.²⁹ The thesis of emptiness precludes primary existents. If nothing has independent existence and objectivity, there are only conventional existents. Secondly, the thesis of emptiness entails non-realism and rules out ultimate truth.³⁰ According to the thesis of emptiness, all objects, including what is commonly referred to as “objective reality,” lack independent existence and objectivity. Contrary to its name, “objective reality” arises from the imposition of a conventional subjective-objective distinction and originates from our conceptual and linguistic endeavors. In the absence of objective reality, there remains nothing for any ultimate truth to depict. Hence, for Nāgārjuna, just as there are only conventional existents, there are only conventional truths.

Zhiyi endorses Nāgārjuna’s thesis of emptiness and its conventionalist consequences. In his works, he repeatedly cites Nāgārjuna’s verse to assert the emptiness and conventionality of all objects.³¹ Moreover, Zhiyi embraces Nāgārjuna’s middle way, which avoids the extremes of getting lost in conventionality and starving in emptiness. This balanced approach gains further insight from two aspects of conventionality. Firstly, conventionality has a deceptive aspect. The meaning of conventionality expands as its original Pāli term sammuti—indicating collective agreement and everyday experience—undergoes Sanskritization to become samvrti, gaining the additional connotation of covering and concealing.³² This added layer discloses the deceptive aspect of conventionality, which can be explained by the initial meaning of conventionality. Once conventional objects and truths are ingrained in our everyday thinking and are validated by everyone around us, they rouse no questions. We tend to misunderstand our own verbal and conceptual constructions as being objective, definite, permanent, and unconditional. The deceptive aspect of conventionality explains why focusing solely on conventionally constructed objects tempts us to reify them and mistake them as independent and objective entities. Therefore, to correctly understand conventionality, one must grasp the truth of emptiness.

Secondly, conventionality plays a significant role in facilitating successful practice. In addition to samvrti, the Sanskrit word vyavahāra is used for conventionality. The notion of vyavahāra is often associated with conventional transaction laws in classical Indian thought and society,³³ and for Nāgārjuna vyavahāra characterizes the interpersonal, transactional aspect of everyday practice, emphasizing the customary ways of speaking and talking that generally lead to success in meeting mundane goals.³⁴ The Chinese translation of vyavahāra, su 俗, is similarly associated with social customs and worldly practice. Moreover, the practical aspect of conventionality ties to skillful means (Sanskrit: upāya), which is extensively discussed in the Lotus Sūtra. Consider the well-known burning house parable in Chapter 3 of the sūtra:

One day, a rich man’s house was on fire. His children were playing inside and ignored their father’s warnings. The rich man used skillful means and told the children that outside were carts pulled by goats, deer, and oxen. Because the children wanted these carts, they raced outside. After the rich man coaxed the children to a safe place, he gave each child a cart—not the promised ones, but well-decorated ones pulled by white oxen.

The rich man told a lie. Because the lie saved lives, it was accepted and encouraged in the burning house situation. Nonetheless, the rich man’s lie was only provisionally and conditionally endorsed. Once the children left the house, there was no need to hold on to the lie. Zhiyi gives his highest praise to the Lotus Sūtra. For him, conventional truths and existents are similar to the rich man’s lie. They are provisionally accepted when they are useful and practical, and they may be rejected when the goal of our practice shifts or our circumstance alters. The practical aspect of conventionality explains why emptiness should be balanced with conventionality. If merely focusing on emptiness, according to which all objects lack independent existence and objectivity, one is tempted to fall into the extreme nihilistic position that eradicates all objects. But this would be detrimental to everyday practice. The practical aspect of conventionality provides a guide for conditionally accepting objects based on their uses, even though they are empty of independent existence and objectivity.

The deceptive and practical aspects of conventionality thus shed light on why conventionality and emptiness complement each other and form an integrated unity. Regarding how we should view and treat objects, Zhiyi advises us to view all objects as conventional and treat them like useful fictions, similar to coordinate systems. While recognizing that coordinate systems do not exist in the physical world, we posit them and assert claims about them because they are useful for us to understand, calculate, and communicate spatial relationships between physical objects. Such an acceptance is conditional, and these systems become useless and even counterproductive if we aspire to find objective coordinate axes in the physical world.

Given that the middle way is the balance of conventionality and emptiness, all three of emptiness, conventionality, and the middle way are inseparable and perfectly integrated. As Zhiyi puts it in The Profound Meaning of the Lotus Sūtra:

The “perfect threefold truth” means that it is not only the middle way which completely includes the Buddha-dharma, but also the real truth [the truth of emptiness] and the truth of conventionality. The threefold truth is perfectly integrated; one-in-three and three-in-one.³⁵

Zhiyi also says in the synopsis of The Great Calming and Contemplation:

[From the point of perfect teaching,] it is emptiness; it is conventionality; it is the middle. Although three, they are one; although one, it is three. They do not obstruct each other. The three are all emptiness. It is [the aspect] free of verbalization and conceptualization. The three are all conventionality. It is just that [dharmas] exist as verbal constructs. The three are all the middle. It is that the middle is the real aspect [of dharmas]. Even if [the truth about dharmas] is verbalized as emptiness, it ju conventionality and the middle. To apprehend emptiness is to apprehend conventionality and the middle. The same applies to [apprehending] conventionality and the middle.³⁶

Given the unity of emptiness, conventionality, and the middle, the three folds not only entail but also complete each other. This unity is even behind the apparent tension between emptiness and conventionality. For Zhiyi, conventionality indicates the aspect that dharmas exist as verbal constructs, whereas emptiness indicates the inherent limitation of our conceptual thinking and verbal expression. The limitation of our conceptualization and verbalization can be explained by the non-realist consequence of emptiness, according to which the so-called “objective reality” is a fictional product of projecting the subjective-objective distinction and thereby lacks independent existence and objectivity. If so, all our conceptual and verbal attempts to characterize reality are inherently limited, and emptiness represents the aspect free of conceptualization and verbalization. Because conventionality and emptiness enrich rather than cancel each other out, objects simultaneously have a verbal and conceptual aspect and an aspect that is free of verbalization and conceptualization.

Similarly, the unity of the threefold truth can resolve the tension between Zhiyi’s verbalization of the interrelationship between all dharmas and his seemingly mystical remark:

It is mysterious, subtle, and extremely profound. It is neither what can be conceptualized nor what can be verbalized. This is why it is called “the realm of the inconceivable.”³⁷

We can interpret the remark as indicating emptiness, in particular the aspect free of conceptualization and verbalization; and by “the realm of the inconceivable”, Zhiyi means what conceptual minds cannot grasp. Moreover, when Zhiyi develops his thesis of interconnectedness in the context of the threefold truth, he makes the following assertion:

To say that one dharma is all dharmas is that “all dharmas arise through causes and conditions.” This refers to conventional designation and the contemplation of conventionality. To say that all dharmas are one dharma is that “this, I explain as emptiness” and the contemplation of emptiness. To say that neither one nor all is the contemplation of the middle way.³⁸

If the interconnectedness of all dharmas refers to the conventionality of dharmas that is integrated with the emptiness of dharmas, then the interconnectedness of all dharmas is associated with the aspect that is free of verbalization and conceptualization. Provided three links—one between the interconnectedness of all dharmas and conventionality, one between conventionality and emptiness, and one between emptiness and the aspect free of verbalization and conceptualization—perhaps the intention behind Zhiyi’s seemingly mystical remark is not to confuse his readers but to caution them against getting lost in conventionality and forgetting emptiness. Nonetheless, Zhiyi’s interconnectedness of all dharmas and the conventionality of dharmas are apparently different. The former concerns how all dharmas are connected by a total relation, whereas the latter concerns how all dharmas dependently exist. Even if each dharma depends on some other dharma (or dharmas), this does not entail that each dharma depends on every other dharma. Thus, Zhiyi needs to explain how exactly the interconnectedness of all dharmas relates to conventionality.

2.3. Summary

Zhiyi’s discussion of the interconnectedness of objects faces three challenges:

• Clarity: What is the relation between all objects? In what sense does one object have or possess all objects? In what sense is one object all objects?

• Consistency: How to reconcile the seemingly contradictory claims about the relations between objects? Specifically, how to resolve the tension between assertions that one object is all objects, that objects are numerically distinct from each other, and that one object and all objects are neither identical nor distinct?

• Plausibility: How is an extensive thesis of interconnectedness plausible, considering that many objects do not appear to have significant connections?

An additional challenge for Zhiyi is raised by his relation of the interconnectedness of all objects to the conventionality of all objects:

• Coherence: The interconnectedness of all objects and the conventionality of all objects concern different aspects of objects. How does the interconnectedness of all objects arise from the conventionality of objects?

To meet the above challenges, I develop a contemporary Tiantai view by integrating Zhiyi’s view of objects with contemporary philosophical resources.

3.1. An Interest-Relative Account of Identity

We tend to take identity to be numerical identity, which is the absolute relation an object bears to itself and nothing else. We also tend to think that the absolute relation a thing bears to itself obeys the principle of the indiscernibility of identicals, according to which object x and object y do not differ in any aspect if x and y are numerically identical. As we see in §2.1, Zhiyi shares our tendencies and acknowledges that many objects are numerically distinct because they are discernible from each other.

Although numerical identity is an intuitive notion of identity, it is not the only way to understand broader identity claims such as “x is (the same as) y.” Consider the ordinary claim that the person I am now is the same person I was yesterday. An endurantist believes that the person I am now is numerically identical with the person I was yesterday, as I am wholly present at each moment of my existence. In contrast, a perdurantist views that the person I am now and the person I was yesterday as two numerically distinct temporal parts of me. I have these temporal parts just as I have numerically distinct spatial parts, such as my head, arms, and legs. While my temporal parts exist at different times, exhibit various features, and are numerically distinct, they can still be regarded as “the same” in the sense that they fall within the boundary of a single person. For example, Lewis (1976: 21) introduces “I-relation” to describe the connection between different temporal parts of a person. This relation helps to understand how these temporal parts are considered the same, as they all belong to a single, continuant person. How my temporal parts can be numerically distinct as well as “the same” illustrates an alternative notion of identity. This notion relates to how objects are individuated, i.e., how the boundary of an object separates the object from others and encloses what is in the object’s boundary. Individuation and numerical identity are therefore two different notions of identity.

It is worth noting that “boundary” is used as a term of art. The boundary of an object can be spatiotemporal, qualitative, or modal. For example, my teacup occupies some spatiotemporal region, weighs 1 pound, and cannot survive being squashed. The teacup’s location, qualities, and modal features constitute its boundary that separates it from other objects. It is also worth noting that the individuation of objects goes beyond countable concrete objects. Even if we can count neither coffee nor tea, coffee and tea are individuated as two distinct drinks. Even if properties are abstract, repeatable universals, wisdom and compassion are individuated as two distinct properties.

The question of how objects are individuated is intricately intertwined with but differs from the question of existence. For instance, consider whether multiple temporal parts can be considered as a single person. The answer depends on whether there exists a person possessing those specific temporal parts. The intricate relationship between individuation and existence indeed highlights the distinction between the two notions of identity. Numerical identity, unlike individuation, neither presupposes nor precludes existence: a round square’s being absolutely identical with itself does not entail that the round square exists. It is only the case that if any object exists, then it instantiates the absolute identity relation with itself. How many times numerical identity is instantiated depends on the existence and prior individuation of objects. This is why individuation and numerical identity should not be confused with each other.

Identity, understood in terms of individuation, can be relative to some criteria. The idea of relative identity was initially developed by Geach (1967; 1973; 1980), according to whom identity is always—explicitly or implicitly—relative to sortals, which are predicates that classify objects as members of certain kinds.³⁹ For example, one and the same person can be numerically different roller-coaster passengers if the person takes the roller-coaster multiple times; one and the same piece of clay can be different statues if the piece of clay gets remolded from a cat shape to a turtle shape. Geach’s theory has inspired a variety of views under the label “relative identity.” These views share the general idea that identity is relative to some criterion, while they diverge in their approaches to absolute identity⁴⁰ or select distinct criteria for individuation, such as sortals, time, and spacetime.⁴¹

The general idea of relative identity can be made sense by conventionalism about objects and the relativity of individuation. As Dummett (1973: 562–563) explains:

[I]t seems that Geach means us to picture that over which the variables range as an amorphous lump of reality, in itself not articulated into distinct objects. Such an articulation may be accomplished in any one of many ways: we slice up reality into distinct individual objects by selecting a particular criterion of identity.

How objects are individuated and how their boundaries are carved tie to whether objects exist independent of our conventions and interests. When objects exist objectively, we play no role in fixing their boundaries and individuating them. But if objects are not ready-made, they are created and individuated by us. They are our products of imposing artificial boundaries between them. Given that there is no objective way of carving the boundaries of objects, our individuation of objects—whether there is one, two, or more objects—may vary depending on the criteria we employ. Similarly, Griffin (1977) argues that identity is sortal-relative because individuation without a sortal is impossible.

As we have seen in §2.2, Zhiyi is committed to interest-based conventionalism about objects, according to which all objects are conventionally constructed and provisionally accepted because they can lead to successful practice. The conventionality of objects aligns well with the general idea of relative identity. It fits with Zhiyi’s view that we construct and individuate objects by imposing the boundaries that separate them from each other.

Nevertheless, Zhiyi’s interest-based conventionalism about objects inspires distinct criteria for relativizing identity, adding to the common criteria of relative identity such as sortals, time, and spacetime. If the existence of objects relies on the success of our practice, so does our individuation of objects. Interest-based conventionalism thus gives rise to an interest-relative account of identity:

(IRI) Putatively distinct objects are identical—i.e., individuated as one object—if and only if this can lead to successful practice.

Whether something can lead to success varies from practice to practice. For instance, factory-farmed chicken can be extremely successful if our practice is to produce more edible chicken flesh, while it is incredibly unsuccessful if our practice is to minimize the suffering of chickens. Furthermore, what is useful for one practice under one circumstance may not be so for the same practice under a different circumstance. For example, our cravings for salt, fat, and sugar play different roles in varying circumstances. While these cravings were lifesaving for our ancestors, they can be lethal for many people today. Based on these considerations, (IRI) can be further specified as follows:

(IRI*) Putatively distinct objects are identical—i.e., individuated as one object—if and only if this can lead to success for some practice p and under some circumstance c.⁴²

Hence, the version of relative identity that fits Zhiyi’s view is interest-relative and is sensitive to both practice and context.

In light of (IRI*), all objects are like the oceans. Just as we create the five oceans by imposing the boundaries of the Arctic, Atlantic, Indian, Pacific, and Southern, we create objects by imposing the boundaries that distinguish them from each other. Although these boundaries are not objectively real, they can still be useful and posited for human interest. The five oceans, for example, are divided because they can be helpful for activities such as sailing and weather forecasting. Nonetheless, these five boundaries merely represent one of many ways of dividing the same body of water. They can be lifted or replaced if the corresponding distinctions become useless and cumbersome for our practice. When we lift the boundaries between the five oceans and posit one boundary including all of them, there is one ocean. There are four oceans when we divide the water by the equator, the prime meridian, and the 180^th meridian. The analogy of the five oceans illustrates how conventionally constructed objects can be individuated relative to different interests. While there is a single body of water encompassing the five oceans, the use of this analogy does not imply the existence of something beyond all conventional objects. It is crucial to emphasize that, in Zhiyi’s view, all objects are conventionally constructed. Even though there is one body of water encompassing the five oceans, that body of water itself is a conventional construct. Moreover, even if one were to propose the existence of an “objective reality” meant to transcend all conventional constructs, the so-called “objective reality” is a product of imposing the objective-subjective distinction within convention.

While Zhiyi’s view inspires new criteria for relative identity, the new criteria can accommodate existing criteria such as sortals and spatiotemporal features. To do this, we can distinguish ultimate and conditional criteria. Although the schema describes interests and contexts as ultimate criteria for identity, we do not need to appeal to these criteria every single time when we try to figure out how to individuate objects. Many interests and circumstances of our practice stay fairly stable. In these cases, we can use criteria such as sortals and spatiotemporal features as convenient shortcuts to individuate. These shortcuts are conditional in the sense that they depend on the stability of certain interests and circumstances. Once the goal or the circumstance of our practice shifts, we will need to reevaluate and adjust our acceptance of conditional shortcuts. How we should treat conditional criteria is similar to how we should treat our ordinary temporal ordering. Given the theory of special relativity, for most events, there is no fact of the matter as to whether they occur simultaneously. Simultaneity is relative to a frame of reference that specifies the relationship between a moving observer and the observed phenomenon. Learning the relativity of time in one way radically changes our understanding of ordinary temporal ordering, which turns out to be just one of many ways of arranging the chronology of events. However, the relativity of time does not mean we have to abandon our ordinary temporal ordering. Since most of us stably stay in roughly the same frame of reference for our whole life, it is convenient and useful to use our familiar temporal ordering. As beings with limited time and cognitive power, it is impractical to think about other frames of reference whenever we think about time. It is thus perfectly appropriate to accept our intuitive judgments about temporal ordering so long as we are not deceived into thinking that this ordering is absolute. Similarly, we are encouraged to accept conditional criteria such as sortals and spatiotemporal regions when they are convenient and useful, and we should be aware of their conditionality and be ready to abandon them when they are no longer useful. This middle way towards conditional criteria should be no surprise to Tiantai Buddhists. If all objects are useful fictions that we create for our practice, so are sortals and spatiotemporal features.

3.2. The Relative Identity of All Objects

The interest-relative account of identity not only emerges from Zhiyi’s interest-based conventionalism about objects but also enhances his thesis of interconnectedness. By appealing to interest-relative identity, we can develop a thesis of interconnectedness to meet the clarity, consistency, plausibility, and coherence challenges listed in §2.3.

To begin, we can address the clarity challenge by pointing out that interest-relative identity is the relation between all objects and demystify Zhiyi’s two positive characterizations of the relation:

One object shi (is) all objects in the sense that one object (e.g., one single thought) and all objects can be (re)individuated as one single object.

One object ju (has) all objects in the sense that one object (e.g., one single thought) can be (re)individuated as the broadest single object that encompasses all objects.

We can thereby propose the relative identity of all objects:

(Inter-IRI*) One object is identical with all objects—i.e., they are individuated as one single object—relative to some interest. That is, it can lead to success for some practice p and under some circumstance c.

Because Zhiyi’s original thesis has an unrestricted scope, (Inter-IRI*) applies to objects of all sorts. In this view, objects of different ontological categories, including material objects, abstract properties, and particular events, are interconnected by relative identity. Zhiyi’s metaphysics hence inspires a version of relative identity with an unrestricted scope, which has a broader application than existing relative identity theories that are restricted to material objects or particulars.

It is worth noting that, although all objects are individuated as one single object, (Inter-IRI*) is not the monist view that exactly one object exists. The relative identity of all objects goes hand in hand with the relative multiplicity of objects. While objects are individuated as one relative to some interest, practice, and circumstance, they are also individuated as many relative to some other interest, practice, and circumstance. (Inter-IRI*) thus transcends the binary opposition of monism and pluralism about objects that presupposes a definitive number, regardless of its magnitude. The relativity of individuation can be exemplified by the analogy of the five oceans. How many oceans are there? Is it one, four, five, or even hundreds? There is no fixed number, as the count of oceans hinges on how we individuate oceans and their utility within our practices. We move beyond both oceanic monism and oceanic pluralism, for both assume a precise number of oceans.

We can then resolve the apparent inconsistency between Zhiyi’s three claims about identity and distinctness:

These claims can be interpreted in a logically consistent way:

Objects have been individuated as numerically distinct objects because these objects and the boundaries between them have been useful for some practice under some circumstance. However, echoing the plausibility challenge, relative to what interest are all objects individuated as a single object? In other words, how is it useful to replace the boundaries of myriad objects with a single boundary that encompasses all of them? As it turns out, the adequacy of a response to the consistency challenge hinges on the ability to address the plausibility challenge.

The relative identity of all objects, like interest-relative identity, arises from Zhiyi’s interest-based conventionalism about objects. If all objects are conventionally constructed, then identifying them with each other can help free us from the deceptive aspect of existing conventional objects. Removing and replacing existing objects illustrate that these objects are merely artificial, conditional, and provisional. Meanwhile, given our inability to directly discuss the indefinite realm of the inconceivable, employing a singular boundary that encompasses all objects is beneficial, even though this boundary is also a conventional product. By spelling out exactly how the interest-based conventionality of objects gives rise to the relative identity of all objects, this response addresses the plausibility challenge while simultaneously tackling the coherence challenge.

3.3. The Threefold Interconnectedness

The conventionality of objects, which is integrated and balanced with the emptiness of objects in the middle way, constitutes one of the three folds of the dependent nature of objects. Similarly, the relative identity of all objects, emerging from the conventionality of objects, represents one of the three folds of interconnectedness. The other two folds of the dependent nature of objects, namely, emptiness and the middle way, also shed light on the interconnected nature of objects.

Emptiness leads to the non-separateness of all objects. If objects are empty due to the absence of objectively real boundaries, then objects are not genuinely separated. This can again be exemplified by the relationship between the five oceans, which are not inherently separated by the boundaries we construct and postulate.

Moreover, just as the middle way integrates and balances conventionality with emptiness, the relative identity of all objects is similarly integrated and balanced with the non-separateness of all objects to avoid falling into the extremes. Focusing solely on the relative identity of all objects can lead to reifying a single object encompassing all objects. Conversely, solely emphasizing the non-separateness of objects can lead to an impractical position that disregards boundaries and the corresponding objects they define. This is why the non-separateness and relative identity of all objects enrich each other and contribute to a comprehensive and balanced understanding of interconnectedness.

Figure 1: The Three-Fold Dependent Nature and Interconnectedness of All Objects.

As the above diagram (Figure 1) encapsulates, three folds of interconnectedness arise from the three folds of the dependent nature of objects. Moreover, the three folds of interconnectedness mirror the harmonious integration of emptiness, conventionality, and the middle way and form a unity.