1. Introduction

From ancient statesmen, kings, emperors, and philosophers to contemporary nationalist thinkers and Chinese international relations scholars, tianxia has been an integral concept and consistent theme looming the imagination of the Sinitic world. The concept of tianxia, which first emerged as a plain spatial designation referring to the area under Zhou rule, has since been examined from a range of disciplinary perspectives [1,2]. Its evolving meanings and multifaceted connotations over time have led to its conceptualization as the ordering principle of Sinitic cosmology, a cultural and moral construct, and a political realm in which kings and emperors aspired to establish Great Unity (大一统) and universal rule [3].

Extensive studies have examined tianxia from an anthropological perspective, analyzing the tianxia-ordered Sinitic cosmology as shaped by the “asymmetrical relationship between Heaven and Earth,” the Mandate of Heaven, and associated sacrificial rituals [4]. While these mythical and cosmological elements are indeed interwoven with the cultural and political ontologies of tianxia, they are not addressed within the confines of this paper. Instead, I adopt a historical approach and interpretive framework that attempt to construct a coherent narrative of the political primacy of tianxia among a myriad of its rich meanings and connotations.

This paper is situated within earlier debates on the political and cultural–moral primacy in the conceptualization of tianxia. The seminal work of Joseph Levenson distinguishes the concept of tianxia, signifying the abstract and imagined totality of the “(Chinese) empire” and civilization from that of guo (state) [1]. Accordingly, tianxia transcends the geographical empire, representing the civilizational ideal or “regime of values,” which embodies universal moral order, Confucian ethics, and kingly virtues (王道) [1]. Guo, by contrast, reflects a “regime of power,” a pragmatic political unit of governance centred on territorial control, military capacity, and bureaucratic administration [1]. It follows that tianxia and guo, as regimes of values and power, operate in distinct and mutually exclusive spheres of the moral and civilizational versus the political and instrumental. In response, Yuri Pines challenges the dichotomy between a cultural tianxia and a political guo, arguing that in early political thought, especially during the Zhanguo period, the “regime of values” and the “regime of power” were not opposed or in tension as Levenson suggested but rather deeply intertwined and mutually constitutive [2].

Along a similar line, this paper argues that tianxia is, first and foremost, a concept of political power rooted in the imagination of an orderly and ideal political realm guiding the search and aspirations for a unified world along the Sinitic civilizational line. In other words, tianxia is not just a “regime of values” but an imagined political realm (“regime of power”) over which the assertion of unified governance is not only tangible but also aspired. The boundaries or spatial configuration of this realm evolved through the yi-xia distinction (夷夏之辨), functioning as a politicized inclusion-exclusion mechanism that defined the civilized “Self” against the barbaric “Others”. Having established the historical transformations of tianxia, the paper then critically examines recent attempts to extrapolate and generalize the concept into a contemporary theory of world order, exposing the teleology, anachronism, and essentialism embedded in this process. It concludes by considering how one might reconcile the need for a philosophical foundation for theory with a historically grounded approach that avoids flattening or distorting the meaning of tianxia in its original context.

2. Historical transformations of tianxia

2.1. The origin of tianxia

The earliest recorded appearance of tianxia (天下) dates back to the Western Zhou period (1047–771 BCE), appearing in the shao gao (召誥) chapter of the shang shu (尚書), which emphasizes that the king should govern not through punishments, but by establishing himself as a moral exemplar for the people under Heaven [1]. Similarly, the often cited eighth-century BCE ode “Bei Shan” (北山) ties tianxia to the emerging Sinitic moral-political order, declaring: “All under Heaven belongs to the King; all who dwell upon the land are his subjects” [1,4]. Although it remains unclear whether tianxia in these early contexts functioned as a fixed compound or a more literal designation (天之下), both instances likely refer to the territory directly under Zhou royal control [5]. Thus, tianxia originally emerged as a plain geographical term rather than a normative or cosmological concept, replacing the Shang-era spatial designation of sifang (四方) [2].

In examining the evolution of spatial terminology across the classical and imperial periods, Mingming Wang proposes a conceptual framework in which guo denotes the “realistic geography” of territories under direct political control, while tianxia refers to an “imaginary cosmography” through which the Mandate of Heaven legitimizes the king’s or emperor’s authority beyond the concrete boundaries of any single polity [4]. Viewed in this light, tianxia, in its earliest usage, had yet to acquire the expansive, universal connotation it would later assume. Rather, it reveals an early conflation of pragmatic territorial governance with cosmological imagination during the Western Zhou period. It is also important to note that tianxia emerged as a spatial designation against the backdrop of declining Zhou royal power, as the king ceded control of fiefs to regional lords. As Pines argues, this political decentralization and fragmentation resulted in the limited scope of tianxia, referring specifically to the royal domain under the direct rule of the Son of Heaven [3]. As a result, tianxia was more constrained than the broader concept of zhongguo (Central States), which predates tianxia, denoting with less ambiguity the entirety of polities (both the royal domain and the feudal states) that followed Zhou-era ritual norms [2,3].

2.2. Early conception of tianxia as a cultural realm

Unlike its contemporaneous counterparts, such as the political concept of the “Central States” and the geographical notion of sifang, tianxia functions as a more inclusive and adaptable vehicle of meaning, receptive to cultural and political reinterpretation [6]. This owes in large to its origin in several interconnected concepts, including tian 天 (Heaven), the highest deity of Zhou and a foundational element of Sinitic cosmology, tianming 天命 (Mandate of Heaven), which served to legitimize rulership, and tianzi 天子 (Son of Heaven), a common designation for Zhou kings [2,6]. As a result, the connotations of tianxia gradually expanded, first in cultural dimensions, then increasingly in political terms.

During the Chunqiu period (770–476 BCE), as flourishing philosophical traditions shaped the discursive space, tianxia underwent a significant transformation in both its conceptual meaning and spatial scope. Heavily influenced by emerging Confucian thought, the Zhou king, mandated to rule as the Son of Heaven (tianzi), was positioned at the apex of the moral and ritual hierarchy within tianxia. This divine authority not only legitimized the king’s claim to political control, but also bound him to uphold moral responsibility for maintaining harmony and order across tianxia through rites (li, 礼) and moral virtue (de, 德) [4,7]. Additionally, frequent diplomatic interactions among feudal states further crystallized a sense of cultural unity among the elites, contributing to the increased usage and evolving interpretations of tianxia [5]. This development aligns with Levenson’s conception of tianxia as a cultural realm or “regime of values,” wherein it came to embody the universal cultural norms, rites, and ethical standards shared and practiced by the Zhou king, feudal lords, and the ruling aristocracy of the Chunqiu states, contributing to a tianxia-based moral universe [1].

This culturally unified and homogenous “regime of values,” in turn, functioned as a core factor defining the civilized self (xia 夏) against the barbaric others (rong di 戎狄) in the spatial configuration of tianxia [8,9]. The question that follows, then, is where do the boundaries of the “imaginary cosmography” lie in relation to the perceived Others (rong di) and the “realistic geography” of guo? The yi–xia distinction, or Sino-barbarian dichotomy, has long been a foundational concept in Sinitic political thought and classical writings [8]. It operates as a concentric civilizational system, wherein the Son of Heaven and his court occupy the innermost circle as the moral and ritual center of tianxia [4]. Surrounding this core are the feudal lords of the Central States (zhongguo), followed by increasingly peripheral groups, culminating with the barbarians of the corners (si yi 四夷) deemed as culturally and ritually inferior [8,4]. During the Chunqiu and Zhanguo periods, the nomadic tribes were systematically excluded from the imagined realm of tianxia, perceived as outsiders owing to their barbaric practices and behaviours [2]. Their exclusion is instrumental in understanding the spatial limits of tianxia. For instance, a Zhou minister’s complaint of Rong (戎) incursions into the Central States goes that: “the Rong possess Central States (Zhongguo)—whose fault is it, Hou Ji (the Zhou progenitor) cultivated All under Heaven, but now the Rong rule it—is it not a real problem? (戎有中國,誰之咎也?后稷封殖天下,今戎制之,不亦難乎?) [2]” The parallel reference to the Central States and tianxia in this context suggests that the two were used interchangeably and thus shared the same spatial extent. This indicates that tianxia expanded not only in its connotations, taking on additional cultural significance but also in its spatial scope, coming to encompass the same regions as denoted by Central States.

2.3. A realm of Great Unity: politicization of tianxia

While the view of tianxia as a cultural realm remained prevalent among the aristocrats, statesmen, and feudal lords, its political dimension gained momentum and became the dominant interpretation during the Zhanguo period (475–221 BCE) [5]. Three interconnected factors contributed to the politicization of tianxia. First, the further decline of Zhou royal authority and the disintegration of the feudal system led to political fragmentation and intensified military conflicts among numerous de facto independent states [1]. Meanwhile, cultural unity within the self-contained Sinitic sphere contributed to aspirations for enduring stability in the political realm [5,10]. Additionally, the devastating interstate wars also promoted Zhanguo thinkers to search for lasting peace [10]. Together, these conditions fostered a common aspiration for the Great Unity (大一统) and political unification as the prescribed solution to the turmoil. As Mengzi noted, “Stability is in unity [3].” Second, the rise of peripheral states, such as Chu and Qin, with enhanced military and organizational capabilities, made conquest and the political unification of tianxia by a single state feasible [10]. Third, and perhaps most importantly, the regular migration of statesmen and Zhanguo thinkers (纵横家) across state borders to preach their philosophies of statecraft for intellectual influence and political appointment popularized tianxia-centred political discourse [4].

The politicization of tianxia transformed it into a concrete political unit and realm in which the establishment of universal and centralized rule was not only possible and aspired to, but also perceived as heavenly ordained. The movement of thinkers across the Zhanguo states in search of patronage was significant in its own right, as their ultimate objective was to assist feudal lords in achieving peace through unification of tianxia. Political discourses such as “possessing All under Heaven” (you tianxia 有天下), “being King of All under Heaven” (wang tianxia 王天下), and “ruling All under Heaven” (zhi tianxia 治天下) proliferated during this period [2]. This evolving vocabulary expanded the political imagination of kings and feudal lords, encouraging ambitions that extended beyond state boundaries to encompass the entirety of the known world. As a result, tianxia effectively became an object of rule whose possession both symbolized and fueled interstate competition for universal supremacy.

The politicization of tianxia continued in Qin’s unification of Zhanguo states and the proclamation of King Zheng of Qin as the First Emperor, who brought about Great Unity in its truest sense, fulfilling the heavenly mandate to pacify tianxia [2,5,10]. The political primacy of tianxia’s meaning and interpretation is evident in its close association with universal political unity, as reflected in the stone inscriptions commissioned by the First Emperor, which declare that “all under heaven, hearts are gathered, and wills are aligned; tools and measurements are made uniform, and writing scripts standardized… the emperor has unified all within the seas, organizing it into prefectures and counties; under Heaven, peace prevails (普天之下,摶心揖志.器械一量,同書文字.今皇帝並一海內,以為郡縣,天下和平).” The centralization and standardization of tools, measurements, and scripts became the means towards asserting universal rule in a unified tianxia. The inscriptions clearly suggest the centrality of pacifying and unifying tianxia in the First Emperor’s proclamation of his historic accomplishments, which in turn embodies the deep connection between political unification and the concept of tianxia.

The political primacy of tianxia was further consolidated with the concept transformed into what Pines characterizes as an “imperial ideology” during the reign of Emperor Wu of Han (汉武帝) [3]. While framing tianxia as an expansionist ideology offers considerable explanatory power, it risks anachronism by imposing modern political categories onto historical contests. Nonetheless, during Emperor Wu’s reign, tianxia clearly functioned as an ideational force legitimizing and propelling military expansion beyond the territorial boundaries reached by any of his predecessors.

Han ruling elites not only inherited the territorial extent and administrative apparatus of Qin but also embraced its ambition for political unification and the assertion of universal rule over the known world—an ambition deeply rooted in the logic of tianxia [3,5,10]. Dissatisfied with the failed diplomatic efforts and the defensive posture of his predecessors toward Xiongnu, Emperor Wu launched prolonged military campaigns aimed at permanently resolving the Xiongnu threat while extending Han authority beyond both Central States and Qin frontiers [3]. In this process, the ideational framework of the yi–xia distinction played a role markedly different from that of the Chunqiu period. Rather than advocating for the outright exclusion of culturally “inferior” nomads (yi), Han statesmen and thinkers increasingly viewed them as potential subjects of the Han tianxia, contingent upon their successful acculturation and assimilation [5,9]. Their lands, in turn, came to be regarded as rightful extensions of the imperial domain. Texts of the Gongyang Zhuan dominated political discourse, which explicitly identifies expansion into the lands of the yi as the rightful responsibility of the Son of Heaven to unify tianxia and bring civility to the backward barbarians, akin to a civilizing mission [3].

The expansionist and civilizing impetus stemming from the political connotations of tianxia complicates Levenson’s binary characterization of tianxia as a “regime of values” and guo as a “regime of power.” The incorporation of substantial alien territories into Han political control in the north and west suggests that the universality of tianxia extended beyond moral and cultural values [10]. The impulse to civilize the backward yi was secondary to Emperor Wu’s military campaigns. Rather, it was the political drive—rooted in the ideal of universal unity under tianxia—that motivated imperial expansion, after which the alien peripheries came to be seen as necessary, if not integral, to the imagined totality of empire [3]. In this historical episode, therefore, tianxia functioned, in and of itself, as a militaristic and imperialistic “regime of power,” revealing the political primacy of the concept.

Moreover, the politicization of tianxia transformed it from an abstract spatial and cultural reference into a concrete political entity, within which universal rule and Great Unity were to be realized. The Qin unification, Han imperial expansion, and the dynamic inclusion and exclusion of the “other” defined in contrast to the Sinitic “self” collectively reshaped the Sinitic political imagination, extending the conceptual boundaries of tianxia beyond guo, and its geographic scope beyond the Central States [4,9].

The political primacy of tianxia’s connotations and interpretations persisted beyond Qin and Han, as the “realistic geography” of guo was redefined during dynastic transitions, either aligning with or diverging from the “imaginary geography” of tianxia [4]. The tributary system adds further complexity to the boundaries of the aspired political universality underpinning tianxia, as tributary polities were included or excluded along the shifting lines of the yi–xia distinction [8].

3. Teleological reinvention of tianxia

3.1. From Great Unity to great harmony: the decline of tianxia during late Qing

Heightened diplomatic exchanges and successive military defeats by imperial powers during late Qing caused a bitter realization that the Sinitic civilizational core was no longer situated at the moral, political, or geographical centre of the world [11]. The dynastic state in transition suddenly lost its long-held claim to civilizational superiority and centrality it once envisioned through the tianxia framework [4]. Late Qing intellectuals were confronted with the imperative of reconciling the past glory with the current predicaments. As a result, they embarked on a project of reinventing the Sinitic world-vision inherent in tianxia and repositioning the emerging Chinese nation-state in the modern international system [11].

This project of state- and identity-building faced significant challenges. The self-seclusion and hegemonic regional presence of Sinitic civilization fostered a Sinocentric worldview that relegated distant others to the margins [6]. Similarly, the multiethnic, dynastic-imperial identity of past Sinitic polities hindered the formation of a state identity comparable to the Western norm of the nation-state. According to Zhitian Luo , the Sinitic political imagination ties imperial subjects directly to the dynastic rulers who were mandated to rule tianxia, in an absence of a well-defined intermediary unit of state (guo) [11]. These structural constraints necessitated parallel efforts to reinvent both the state (guo) and the world, as well as to redefine China’s place within it. Similar to the teleological reinvention of Zhongguo and “China,” tianxia underwent a transformation in which intellectuals such as Kang Youwei and Liang Qichao stripped the concept of its traditional political connotations [5]. The Sinocentric universalism and aspiration for Great Unity embedded in the historical conception of tianxia were consciously abandoned in pragmatic recognition of China’s limited national strength. Shijie (世界), originally a Buddhist concept, was redefined to replace tianxia as the Chinese equivalent of “world [11].” In so doing, China was positioned within the Westphalian international system on equal footing with other nation-states. This further rendered the yi-xia distinction obsolete, which used to guide the inclusion and exclusion of members of the Sinitic tianxia, because of the asymmetrical power relations between Qing and imperial powers. Although the notion of tianxia or shijie as a political realm persisted, the imperial ambitions to establish a Sinocentric civilizational hierarchy and realize Great Unity were effectively removed from late Qing narratives and political discourse [4]. Instead, tianxia’s meaning contracted and retreated to the moral domain, with Kang and Liang advocating for the apolitical ethical ideal of “Great Harmony” (datong 大同).

The parallel projects of identity-building and repositioning of China in the international system by reinventing tianxia ignites debate on the evolving spatial configuration of the concept during late Qing. Levenson defines this process as a “contraction of China from a world to a country in the world [1].” Indeed, the political and imperial connotations of tianxia were systematically censored by Kang and Liang for the sake of enlisting the emerging Chinese nation-state in the modern international system [11]. However, not only did tianxia retain its significance in the moral realm, but its spatial scope also expanded beyond the Central States and continental East Asia, which came to encompass or converge with the world in its truest sense through the invention of shijie. This has effectively laid the groundwork for future extrapolation of tianxia to create a paradigm of Chinese international relations theory underpinned by Sinitic universalism.

3.2. Resurgence and the making of tianxia-ism

China’s rise over the past decades has prompted Chinese international relations (IR) scholars to revisit tianxia and its implications for the global order, picking up where late Qing thinkers left off [12]. This marks a striking reversal from the late Qing intellectual trend, in which tianxia was systematically dismantled and Sinitic exceptionalism silenced in favour of the prevailing Westphalian system [11]. The multifaceted nature and evolving interpretations of tianxia make it a promising historical source for IR theorization [12]. As previously discussed, tianxia served as a guiding principle through which dynastic rulers and intellectuals envisioned the cultural, moral, and political order along the Sinitic civilizational line [2,5,7]. Its reinvention in the late Qing period further embedded an international dimension into a concept that had historically been confined to continental East Asia.

Extrapolating from ancient texts and discourses on tianxia, Zhao Tingyang developed a model of world governance and normative theory grounded in four core propositions. First, Zhao reconceptualizes tianxia as an ideal world order characterized by a globally inclusive system that encompasses all peoples, cultures, and political entities [7]. Thus, “All under Heaven” signifies that there is no outside and no entity excluded from the envisioned universal Great Harmony (datong). Second, tianxia is conceived as an inherently harmonious, hierarchical, yet benevolent system in which a central authority (historically China, but conceptually any moral exemplar) governs through virtue (de, 德) and sustains order and stability [7,13]. Third, Zhao contends that the tianxia normative framework offers a remedy to the conflict-prone Westphalian international system, which he characterizes as a “non-world” a fragmented realm driven by power struggles and zero-sum competition among sovereign nation-states [13]. Fourth and most importantly, Zhao argues for the necessity of a world institution or central authority, akin to but more empowered than the United Nations, founded on the preceding principles to escape global anarchy and establish a world order of Tianxia-ism [7,13].

Zhao is not mistaken in attempting to construct a paradigm grounded in tianxia. The concept, rich in textual evidence and possessing considerable analytical breadth and depth, offers a valid, if not the most fitting, foundation for a Chinese school of international relations theory [12]. While the feasibility of realizing such an idealistic world order remains debatable, it is the absence of a sound historical foundation that undermines the credibility of Zhao’s Tianxia-ism [12].

It may be overly demanding to hold international relations theorization to the same historical rigor required to avoid teleological interpretations since “theory is always for someone and for some purpose” [14]. However, teleology is particularly detrimental when formulating a global theory based on tianxia. Unlike late Qing thinkers who reinterpreted tianxia primarily within a moral framework, the Sinocentric implications of Zhao’s Tianxia-ism are left unchecked and arguably become more pronounced as China emerges as an aspiring hegemon on the global stage. Although Zhao contends that the proposed Tianxia-based world order does not require China to assume any exceptional role, his theoretical propositions invite skepticism regarding the potential political motivations behind the project, rendering it unconvincing to many Western IR scholars. Without a nuanced and historically grounded justification of this methodology, Tianxia-ism risks misinterpretation as a theory for China than a theory of China. Additionally, the first theoretical proposition of all-inclusiveness of tianxia-based world order represents a clear case of teleological reinvention for the sake of theoretical attractiveness, which tweaked or willingly ignored tianxia’s historical contexts. As explicated in section two of this paper, tianxia’s political-spatial configuration was conditioned by the often-exclusionary mechanism of the yi-xia distinction [8,9]. Historically speaking, inclusion into the Sinitic tianxia has always been conditioned by dynastic political reality and particularity.

Second, Zhao’s theorization falls into the common historical trap of anachronism, imposing contemporary understandings onto ancient texts and discourses. As discussed earlier in this paper, tianxia did not acquire a truly “international” scope until its late Qing reinvention, which was previously constrained only to the Sinitic sphere [10]. In other words, tianxia represented a limited form of universalism, bounded by the cultural and political construct of Sinitic civilization. Overlooking this historical nuance, Zhao assumes that Great Harmony (datong), as imagined by pre-Qin thinkers, extended beyond the Zhou-era known world to encompass the unknown “nations [7].” Likewise, by retroactively labeling classical and imperial-era statesmen and thinkers as “Chinese,” Zhao presumes a continuity of political thought that seamlessly feeds into a coherent “Chinese” theory of international relations [7,13]. Yet this is clearly anachronistic, given that the very concept of “China” (Zhongguo) in its modern national form did not emerge until the late Qing. This historical disjuncture complicates the qualification of Tianxia-ism as a distinctive “Chinese contribution” to the field of IR.

Third, and closely related to the previous critique, is the essentialism embedded in Zhao’s theorization. Central to his theory of Tianxia-ism is an entrenched dichotomy between a peaceful, morally grounded tianxia-based world order and a conflict-prone, anarchic Westphalian international system [13]. Zhao treats peace, harmony, virtue, and political ethics as immutable and timeless attributes of tianxia and, by extension, as essential characteristics of “Chinese” political thought. However, historical evidence suggests otherwise, revealing a far more complex and dynamic reality in which tianxia was continuously reinterpreted and transformed across dynastic transitions. Notably, there was a marked gap between tianxia as an inclusive moral discourse and its deployment to justify political unification under Qin or imperial expansion during Han [5]. In other words, there is no immutable or monolithic tianxia that is inherently harmonious or inclusive [6,5,8]. Taking ancient rhetoric at face value and interpreting it through essentialist, teleological, and anachronistic lenses not only oversimplify the multiplicity of tianxia’s meanings, but also undermine the intellectual credibility of the emerging Chinese School of IR.

4. Conclusion

First emerging as a geographical reference to the royal domain of the Zhou kings, the concept of tianxia evolved over time, incrementally taking on cultural, moral, and political connotations as dynastic rulers, statesmen, and thinkers reinterpreted and mobilized it for diverse purposes. Rooted in interconnected elements of Sinitic cosmology, such as tianming (Mandate of Heaven) and tianzi (Son of Heaven), tianxia came to represent, during the Chunqiu period, a unified cultural realm or a “regime of values” that embodied universal norms and ethics legitimizing the divine authority. Political connotations began to dominate from the Zhanguo period onward amid growing anxieties over instability and the quest for unity. This politicization culminated in the emergence of a tianxia-based imperial discourse, which was employed to justify the Qin unification under the First Emperor and Emperor Wu’s imperial expansion as efforts to pacify and establish Great Unity across tianxia. As a result, tianxia was transformed into a concrete political unit or “regime of power,” akin to guo, over which the assertion of universal rule and Great Unity was not only possible but also aspired to, manifesting the political primacy inherent in the meanings of tianxia. The multiplicity of tianxia’s meanings and connotations evolved alongside changes in its political-spatial configuration, which gradually expanded from the royal domain of the Zhou king to encompass the Central States (zhongguo) and, eventually, territories beyond. Yi-xia distinction guided the evolving boundaries of tianxia, functioning as a conceptual mechanism that defines the Sinitic “Self” in contrast to the barbarian “Others.” It served to include or exclude both the peoples and territories in or from what was considered to be “under Heaven.”

The interpretation of tianxia retreated into the moral realm in the wake of humiliating defeats by Western imperial powers. In response, late Qing intellectuals reimagined tianxia as shijie (world), stripping it of its former imperial connotations to facilitate the transition from empire to nation-state. Yet this contraction of tianxia’s meaning was accompanied by an expansion of its imagined boundaries, freeing the concept from its earlier Sinitic civilizational constraints. This shift laid the conceptual groundwork for the later theorization of tianxia as a “world theory” by contemporary Chinese IR scholars. Zhao Tingyang is not mistaken in selecting tianxia as the foundation of his theoretical project. However, the absence of a sound historical approach significantly undermines his core propositions regarding a superior, all-inclusive, and orderly tianxia-based world order. While any theorization requires a robust philosophical grounding, it must also reconcile reductionist theoretical extrapolations with the historical complexities and transformations of the concept. A historically grounded approach demands that scholars historicize tianxia, justify their empirical logic, and avoid the common pitfalls of unchecked teleology, anachronism, and essentialism