From the Great Void to Moral Practice: Ira Kasoff’s Systemic Reconstruction of Chang Tsai’s Ontological Ch’i in Cosmology, Human Nature, and Sagehood

Abstract

This paper examines Ira E. Kasoff’s systemic interpretation of Chang Tsai’s Neo-Confucianism in his The Thought of Chang Tsai (1020–1077), focusing on Kasoff’s reconstruction of Ch’i (qi, 气) as the ontological foundation of Chang’s philosophy. Through a trichotomous translational strategy—distinguishing between “Ch’i”, “ch’i”, and “qi”—Kasoff systematically integrates Chang’s cosmology, human nature, and ethics into a coherent framework. He argues that Ch’i (e.g., Great Void, taixu, 太虚) serves as the primordial substance underlying all existence, while ch’i and qi explain the generation of phenomenal forms and moral agency. Kasoff highlights how Chang’s Ch’i-centric ontology refutes Buddhist illusionism and Daoist non-being, positing yin–yang interactions as the self-generative mechanism of the cosmos. Central to Kasoff’s analysis is Chang’s dual-nature theory of heavenly nature (天地之性, as the inherent goodness of Ch’i) and physical nature (气质之性, as the individualized limitations of ch’i); Kasoff demonstrates how Chang’s emphasis on learning (xue, 学) aims to transform nature and restore heavenly nature, culminating in sagehood as the realization of cosmic harmony. Additionally, by contrasting Chang’s Ch’i-based system with Cheng-Zhu Neo-Confucianism, Kasoff underscores its originality—a dynamic, materialist ontology that bridges metaphysics and ethics.

1. Introduction

The philosophy of Chang Tsai1 (张载, 1020–1077) in the Northern Song Dynasty occupies a crucial and distinctive position in the rich tapestry of Chinese philosophical history. Chang is widely recognized for his Four-Sentence Doctrine (横渠四句), which articulates four ethical and societal imperatives for intellectuals, advocating “establishing the heart for the universe, determining the destiny for the people, continuing the lost scholarship for the sages of the past, and initiating a peaceful world for all generations为天地立心,为生民立命,为往圣继绝学,为万世开太平”2. His works, including Correcting the Unenlightened (Zheng Meng, 正蒙), Western Inscription (Xi Ming, 西铭) and Explanation of Classics by Chang Tsai (Jingxue Liku, 经学理窟), present the extensive content of his thoughts, especially those centered around the exploration of cosmology, human nature, and ethical pursuits, thus providing a cornerstone for the development of Neo-Confucianism. However, the complexity of his philosophy and its various interpretations have led to a situation described by Ira Kasoff as follows:

the content of Neo-Confucian thought is not as well known in the West as is the philosophy of pre-Qin thinkers like Confucius, Mencius and Lao-tzu. Chang Tsai, one of the most interesting of the early Sung philosophers, has not yet been adequately studied in any Western language”

[1]3 (p. ix).

The Thought of Chang Tsai (1020–1077) represents the first monograph by a Western scholar to systematically explore the philosophy of Chang Tsai, and thus “fills a specific gap in (the western scholar’s) knowledge of the Neo-Confucian thinkers who emerged in China” [7] (p. 416). As an important doctoral dissertation, firstly published by Princeton University in 1984, it mainly studies Chang Tsai’s concepts of Ch’i, heaven–earth, and man, his view of sages, and the relationship between Chang and the Cheng brothers (二程, namely, Cheng Hao and Cheng Yi). The author, Ira Kasoff, traveled across the ocean to Beijing in the late 1970s and spent a year studying under Zhang Dainian (张岱年), the master in the study of the Neo-Confucianism of the Song and Ming dynasties4. They had regular weekly discussions on the thought Chang Tsai, and the result was this work, which witnessed the precious history of academic exchanges between China and foreign countries in the early 1980s [8]. Kasoff’s strategy for translating and introducing classical Chinese philosophical concepts is highly enlightening and, due to its representative nature and significance, is particularly worthy of in-depth study. The cross-fertilization of ideas based on his novel interpretations and understandings from his engagement with Chinese philosophy can lead to innovative solutions to contemporary problems and foster a more comprehensive global intellectual landscape.

Accordingly, the principal objective of this study is to dissect the intellectual maneuvers through which Kasoff undertakes a systematic reconstruction of Chang Tsai’s philosophy, predicated upon the ontological5 Ch’i, within the purview of his seminal work. By closely examining the nuances of his translational choices, conceptual reconfigurations, and the overarching framework he erects, we seek to unearth the underlying mechanisms that render Chang’s profound ideas accessible and coherent in a new and systemic context. Thus, exploration is not merely an exercise in textual analysis but a pursuit of epistemic bridges that span disparate philosophical terrains. This research is also an exploration of the philosophical logic behind Kasoff’s translation of the concepts in Neo-Confucianism. It discusses why he reconstructed the semantic aspects of traditional concepts, explaining the reclassification of Ch’i in particular, and clarifies his contributions to the studies of Neo-Confucianism in the Song and Ming Dynasties and even to research on Chinese philosophy.

2. “Ch’i” as a Fundamental Concept in Traditional Chinese Philosophy

Ch’i is one of the most important concepts in Chinese philosophy and culture [9] (p. 1). The concern about Ch’i in ancient China has a long history. The character “气” already appears in oracle bone inscriptions. By the late Western Zhou Dynasty, Ch’i had evolved into a basic philosophical concept. Its original and essential meaning is an objective and mobile material existence, or simply the breath. It was also used to describe an original undifferentiated state from which heaven and earth emerged; thus, people use Ch’i to explain various phenomena. For example, in Guanzi 管子, it says that “When the Ch’i changes, it is called essence6—气能变曰精” (Guanzi: Xin Shu II,管子·心术下). The earliest roots for the explanation of Ch’i in pre-Qin Confucianism can be traced back to The Book of Changes (Yi Jing, 易经, or I Ching), which states that “Production and reproduction is what is called (the process of) change 生生之谓易” [10]. At this stage, it merely introduced the category of Ch’i at the level of heaven and earth, yin and yang, without elaborating on the fundamental nature of Ch’i in detail. In The Analects (Lun Yu, 论语), it is described that when Confucius ascended the reception hall, he held up his robe with both hands, bent his body, and held in his breath, namely, Ch’i. Subsequently, Mencius made significant contributions to the theory of Ch’i. Mencius put forward the proposition of “I am skillful in nourishing my vast, flowing passion-nature 我善养吾浩然之气”, which became an important category in Confucian moral cultivation. He said that “this is the passion-nature: It is exceedingly great, and exceedingly strong. Being nourished by rectitude, and sustaining no injury, it fills up all between heaven and earth. This is the passion-nature: It is the mate and assistant of righteousness and reason. Without it, man is in a state of starvation 其为气也, 至大至刚, 以直养而无害, 则塞于天地之间. 其为气也, 配义与道; 无是,馁也. (Mengzi: Gong Sun Chou I 《孟子·公孙丑上》)”7. Namely, the characteristics of the vast, flowing passion-nature are as follows: It is a kind of righteous qi that pervades heaven and earth, emphasizes morality and justice, and originates from the heart and acts on the external objective world. It is a spiritual realm that is interconnected with all things in heaven and earth. He also proposed cultivation methods related to qi and “Mind 心”, arguing that people can fully develop their inherent goodness through introspection, thereby reaching the realm of the unity of heaven and man. For Mencius, the way of cultivating one’s moral character, righteousness in particular, lies in cultivating the mind and nourishing qi. Mencius’ thought had a significant impact in terms of inspiring Chang Tsai’s theory of Ch’i, among other aspects of this philosophy. Xunzi further expanded on this concept and advocated that all things have Ch’i, stating that:

Water and fire have Ch’i but no life; plants have life but no consciousness; animals have consciousness but no righteousness. Humans have Ch’i, life, consciousness, and also righteousness. Therefore, humans are the most noble in the world 水火有气而无生, 草木有生而无知, 禽兽有知而无义, 人有气, 有生, 有知, 亦切有义, 故最为天下贵也.

(Xunzi: Wangzhi 《荀子·王制》)8.

From this, it is evident that traditional Chinese philosophers began to explore the origin of the universe and the substrate of all things based on the understanding of Ch’i. It highlights the significance of Ch’i as a foundational characteristic of the natural world in the ancient cosmological framework, serving as the starting point for understanding the gradation of existence, and its presence in humans contributes to their special status and moral responsibilities.

During the Han Dynasty, the ideological proposition that “primordial Ch’I (yuanqi, 元气)” serves as the origin of all entities came into being. Dong Zhongshu (董仲舒) was the first to introduce the concept of primordial Ch’i, insisting that the Ch’i of heaven and earth, the yin Ch’i, the yang Ch’i, the Ch’i of the five elements, and the Ch’i of the four seasons all originate from primordial Ch’i. Nevertheless, constrained by the concept of the interaction between heaven and man, the category of Ch’i was distorted into a medium through which heaven dispenses rewards and punishments and manifests its will. Wang Chong (王充), a representative of the classical Ch’i theory in the Eastern Han Dynasty, refuted the theory of the interaction between heaven and man by emphasizing the natural essence of primordial Ch’i, with the intention of rectifying the mystification of the Ch’i theory. However, his theoretical emphasis was primarily centered on critiquing the theoretical trend, without succeeding in constructing a comprehensive cosmology and theory of self-cultivation for Confucianism. It is Chang Tsai, drawing on the different conceptions of Ch’i in pre-Qin Confucians—such as Dong Zhongshu of the Han Dynasty and Wang Chong of the late Han Dynasty—that provided more systematic and in-depth discussions of Ch’i and Ch’i transformation. No previous thinker employed the concept in the same way as Chang Tsai. His work was comprehensively explored and expounded in The Thought of Chang Tsai (1020–1077).

3. The Ontological Primacy of Ch’i: Kasoff’s Trichotomous Framework and Interpretation of Chang Tsai’s Cosmology

3.1. The Ontological Primacy of Ch’i

Ira Kasoff commences his discussion with an introduction to the academic milieu of the 11th century, probing into the interpretation of the emergence of a new generation of intellectual elites and the central issues of their debates: what is the Dao that permeates all things, what is human nature based on this, and what is the Mind? This leads to the exploration of Chang Tsai’s contributions. Kasoff proposes that Chang’s definition of Ch’i enabled himself to re-assert the truth of the world. While rejecting the Buddhist ontology, it formed the foundation of Chang’s view of the universe. This also serves as the starting point of Kasoff’s interpretation, endowing Ch’i with crucial ontological significance. Kasoff concurs with the characterization of Chang’s philosophy as materialism centered around Ch’i. Ch’i is the “most fundamental concept” [1] (p. 36) in Chang’s thought, running through his ideas consistently. As Chang put it, “From the transformation of qi we have the name the Way 由气化, 有’道’之名” [1] (p. 39).” Since everything is generated from Ch’i, the following applies:

All that is above form is called the Way. It is just that the place where being and non-being come together, the place of form and no-form, is difficult to understand. You must understand that ch’i originates here. I claim that qi can unify being and non-being. 凡不形以上者, 皆谓之道. 惟是有无相接与形不形处, 知之为难,须知气从此者, 盖为气能一有无”

[1] (p. 39).

Kasoff believed that in the beginning of the Correcting the Unenlightened, Chang described an original state of undifferentiated Ch’i, the “Great Harmony (taihe, 太和)”, existing prior to discrete objects. It is unitary and “above form (形而上)”. Given that the Great Harmony inherently possesses the yin–yang polarity, it operates on itself to generate all the objects and phenomena within the universe. In its most rarefied form, it has no shape. It also includes the air we inhale, all living creatures, and all non-living things. Due to its inherent nature, Ch’i needs to go through an infinite sequence of condensations to create tangible objects. This is invariably followed by the disintegration of the condensed objects and a reversion to the undifferentiated state. Regarding numerous philosophical propositions such as heaven, Dao, nature, mind, spirit, and form, according to Kasoff, Chang Tsai discussed them in a way that emphasizes the inseparability of substance and function, with the transformation of Ch’i as the basis. Moreover, the concepts of Ch’i and yin–yang, heaven, and spirit together constitute Chang’s view of the universe. Consequently, Ira Kasoff’s research and interpretation have deepened Zhang Dainian’s theory of Chang’s Ch’i-based materialism. It must be mentioned that “ontology” here is framed through Chang Tsai’s Ch’i-centered cosmology, where Ch’i serves as the singular, dynamic substance underlying all existence. Unlike abstract Western metaphysics, ontology here emphasizes Ch’i’s cyclical transformations (condensation/dispersion) and its unification of form and no-form, rejecting dualisms like being/non-being or mind/matter.

3.2. ”Ch’i”, “Ch’i”, and “Qi”: A Trichotomous Translational Strategy

Kasoff argues that Chang Tsai constructed a philosophical ontological view of the theory of Ch’i as the ontological entity of transformation. Therefore, in the translation of “气”, one should accurately understand its rich connotations as a fundamental concept. It is necessary to systematically sort out and reasonably interpret its use, maintaining consistency throughout to dispel misinterpretations caused by its use at different levels. In the previous studies and introduction, Wing-tsit Chan translated “气” as “material force” [3] (p. 495). Siu-chi Huang believes that the translation of “vital force” is more accurate than using “matter”, “material force”, “matter-energy”, etc. [12] (p. 247). Galia Patt-Shamir translated it as “vital power” [13] (p. 223). In general, “Regarding how Ch’i is understood in Europe and America, the following characteristics can be cited: in Germany, the focus is on vital force; in France, the focus is on energy; in the UK and the US, the focus is on inner force” [14] (p. 6). Yet, Kasoff holds that there should be reflection on these common translations, and the approach of simply regarding Ch’i as matter needs to be reconsidered as well. He believes that the translations such as “ether” (Feng Youlan), “ether of materialization” (Thomas Metzger), “configurational energy” (Mansfield Freeman), “air/pneuma/matter-energy” (Joseph Needham), and “passion-nature” (James Legge) can only cover different aspects of Ch’i, and it is difficult to achieve consistency in understanding Chang Tsai’s thought of Ch’i. Because the Ch’i mentioned by Chang not only has different levels but also has different emphases in the interpretations of various chapters and contents, if any of the above-mentioned translations is used consistently, the internal unity of the ideological system cannot be achieved. Therefore, his solution it to “prefer to leave it untranslated, and to try instead to convey a sense of its meaning(s) in the discussion which follows” [1] (p. 163). According to the different connotations, he translates it into three categories in different contexts: “Ch’i”, “ch’i” and “qi” [1] (p. 52):

(1)

“Ch’i”, or “氣” in Chinese, refers to the undifferentiated, primal substance. For example, “气聚则离明得施而有形, 气不聚则离明不得施而无形” is translated as “When Ch’i condenses its visibility comes into effect and there are forms. When Ch’i does not condense, its visibility is not in effect and there are no forms”. This Ch’i is not static but is inherently generative, containing the latent potential for yin–yang interactions that drive cosmic transformations.

(2)

“ch’i”, or “気” in Chinese, denotes the condensed, tangible matter. For instance, “气不能不聚而为万物, 万物不能不散而为太虚” is rendered as “ch’i cannot but condense and become the myriad things; the myriad things cannot but disperse and become the Great Void”. These qualitative variations, such as “clarity” (qing, 清) or “turbidity” (zhuo, 浊), give rise to individual limitations. However, ch’i is not irredeemably fixed. Through learning and ritual, individuals can refine their ch’i, aligning it with Ch’i’s inherent goodness.

(3)

“qi”, or “气” in Chinese, refers to the qi with the above-mentioned dual meanings or ambiguous meanings (when both meanings are intended). For example, “盖为气能一有无, 无则自然生, 气之生即是道,是易” is translated as “When there is non-being, then qi is produced spontaneously. This production of qi is the Way; it is change” [1] (pp. 38–39).

Historically, the Chinese academic community has extensively acknowledged the polysemic nature of qi in Chang’s philosophical corpus. Traditional interpretations often categorize these semantic dimensions along binary axes—tangible and intangible, metaphysical and physical, and congenital and acquired. Nevertheless, such dichotomous frameworks invariably leave an epistemological “gray zone”, a semantic terrain that defies neat classification. This interstitial realm encompasses meanings of qi that operate at the liminal space between these dichotomous divisions, or transcend these categorical boundaries altogether, manifesting as a unifying force that permeates both domains. In contrast, Kasoff offers a more holistic hermeneutic framework that accounts for these nuanced, trans-categorical dimensions of qi. This demarcation greatly explicates the process of Ch’i’s motion and transformation. The original undifferentiated “Ch’i” condenses into tangible “ch’i” through motion, and the latter disperses and reverts to the former, cycling repetitively, thereby constituting the birth and death transformations of all things in the universe. Such demarcation makes the process of Ch’i’s motion and transformation more intuitive and comprehensible, and also proffers a more specific theoretical scaffold for the study of the Ch’i theory in ancient Chinese philosophy.

3.3. Great Void, Yin–Yang and Cosmic Generation

By dividing “气” into “Ch’i” in the original sense and “ch’i” in the sense of condensation, Kasoff classifies it into metaphysical categories. He considered that the most important original contribution of Chang’s philosophy was the attempt to unify the “above-form” and “below-form”, or supramundane and the mundane, as well as being and non-being, with Ch’i. In Chang’s philosophy, “the Void (xu, 虚)” was a form Ch’i itself, and Great Void (taixu, 太虚) was the ontological bedrock of Ch’i as the undifferentiated, primordial substance underlying all existence. Kasoff argues that Chang redefines taixu not as an empty void but as the formless state of Ch’i, thereby refuting Buddhist illusionism and Daoist non-being. For Chang, Great Void is the “original substance of ch’i” [1] (p. 37) in a formless state, from which all phenomenal forms emerge through condensation and into which they dissolve. Kasoff highlights this process with Chang’s metaphor of ice and water: “The condensation and dispersal of qi in the Great Void is like the freezing and melting of ice in water” [1] (p. 38). This analogy underscores Great Void’s ontological primacy: while ice (manifest forms) is temporary, water (undifferentiated ch’i) remains eternal.

Kasoff further emphasizes that Great Void’s dynamic nature—its inherent capacity for change through yin–yang interaction—enables cosmic generation. He writes the following:

“The Great Void is pure; being pure, it is without obstruction. Because it is without obstruction, it is marvelous. The opposite of pure [ch’i] is impure [ch’i]; being impure, it is obstructed. Because it is obstructed, it has form [1] (p. 9).”

Here, Great Void’s “marvelous” (shen, 神) quality lies in its spontaneous, unobstructed movement, generating the polar forces yin and yang. Based on this, he argues that the interaction between yin and yang, as the inherent dynamic properties of ch’i, embodies the “marvelous” creativity of ch’i, generating both natural phenomena and moral order. Kasoff emphasizes that yin and yang are not separate entities but complementary forces within ch’i: “Ch’i is one thing with two substances. Because it is one, it is marvelous; because it is two, it is transformed” [1] (p. 43). This duality is essential for cosmic generation: “The alternation of yin and yang is the Way. […] The Way is the principle of change and transformation” [1] (p. 187).

Kasoff notes that the thought here refutes Buddhist static emptiness and Daoist passive non-action, showing instead an active, self-generative cosmos. In numerous Buddhist doctrines, it is a fundamental idea that the phenomenal world is illusory (huanhua, 幻化): all things are unreal, and only the Great Void behind them is real. According to Kasoff, Chang Tsai deliberately employed the concept of Great Void to refute such perspectives. Buddhist scholars often denoted the phenomenal world as void to expound on its illusory nature. However, Chang interpreted the Great Void in a manner distinct from Buddhists. Seeing the Great Void as essentially Ch’i, he endows it with real physical substance and existence.

Chang emphasized the fact that matter is transitory, being part of a cyclical condensation and dispersal of qi. Here, however, where the passage is part of a longer critique of Buddhism, he emphasizes that physical matter has real existence, and that Buddhists are wrong to call it illusory. Some Buddhist schools believe that because things wither away and disappear, they are ultimately unreal. According to Chang, this fundamental Buddhist premise is incorrect. He maintained that Buddhists did not understand that this disappearance is merely a change in state, from condensed ch’i to the undifferentiated Ch’i of the Great Void, both of which are equally real [1] (p. 43).

The overarching tenet of Buddhist doctrine, as interpreted by Chang Tsai, is to regard the mind as the Dharma and Kong (空) as the ultimate truth. However, Chang’s critique frames Kong as an “illusory void” (幻妄) that negates the reality of the cosmos, a view reflecting his polemical engagement with Buddhist metaphysics rather than a neutral exposition of its tenets. In response, put differently, all things in the universe are neither illusory phenomena nor sheer non-existences. Chang argued that “Buddhists mistakenly hold that the innate nature (benxing) can be altered through subjective will, yet they lack knowledge of how to rationally apply this innate nature to guide their behaviors and lives. Instead, they attribute the origin of heaven and earth to the insignificant factors of the six senses. Since they are unable to fully understand (the truth), Shakyamuni misleads humans who heaven, earth, the sun, and the moon by characterizing them as mere illusions释氏妄意天性而不知范围天用, 反以六根之微因缘天地. 明不能尽, 则诬天地日月为幻妄. Zheng meng: Daxin 《正蒙・大心》”. In its argument that the myriad phenomena of heaven and earth are illusory and unreal due to the eye’s inability to perceive certain existential modalities, Buddhism proposes a negation of empirical reality. Chang critiques this perspective by steadfastly asserting the concrete existence of all worldly entities. He maintains that even the void, far from being a vacuous nothingness, constitutes a latent, imperceptible state of qi, thereby affirming continuity between apparent emptiness and manifest form9.

Also, the Taoist cosmological framework believes that being (you, 有) emerges from non-being (wu, 无), where the void is equated with non-being and Ch’i is identified as being. However, this conceptualization introduces a critical paradox. Within Chang’s Ch’i-centered ontology, the void is described as no-form. This is not as a negation of ontological reality, but to denote its status as undifferentiated Ch’i—a state prior to the condensation of qi into determinate phenomena. Unlike social ontologies, where intangible entities such as social norms derive ontological circumscription from collective intentionality, Chang’s ontology ties circumscription to form, which emerges only when qi condenses into specific phenomenal attributes. The Great Void, as formless Ch’i, cannot be ontologically circumscribed in this sense: it is the generative ground of all things, characterized by fluid potentiality rather than fixed qualitative determinations. Conversely, Ch’i as being is inherently limited by its physical manifestations. This duality raises insurmountable challenges: how can an indeterminate, formless void generate determinate, form-bearing Ch’i? Conversely, how can concretized Ch’i dissolve back into the formless void without violating the essential ontological divide between the two? Kasoff stated the following:

When one knows that the Great Void is Ch’i then there is no non-being……The various savants are shallow and incorrect in their distinction between being and non-being, this is not the kind of study which will exhaust principle

[1] (p. 42)

The transformative relationship between void and Ch’i becomes ontologically untenable, as the qualitative disparity between formlessness and form would preclude such a transition. Chang Thus, the Taoist cosmology collapses under the weight of its own logical inconsistency.

In summary, Kasoff’s interpretation underscores the significance of Chang Tsai’s cosmogony as a theory addressing the conditions, composition, origins, dynamics, transformative processes, and order of life in the universe. By constructing the cosmogonic framework of the Great Void using Ch’i (太虚即气), Chang Tsai critiques Buddhism’s view of the world as illusory and affirms the ontological reality of the phenomenal world. His theory articulates fundamental insights into the composition of reality, the generative roots of all things, and the mechanisms driving cosmic change. Within this system, Great Void and ch’i—interacting harmoniously—emerge as the two primary cosmic elements. Great Void serves as the supreme reality, ultimate origin, and guiding force of the cosmos, while ch’i acts as the material substratum, vital energy, and creative principle underpinning the generation of phenomena. In the process of cosmic generation, Ch’i provides indispensable materiality and vitality for the formation and sustenance of all entities, and Great Void actualizes the inherent nature or essence of all things, endowing them with existential grounding and propelling their continuous transformation. For Chang Tsai, both Great Void and ch’i are ontologically indispensable to cosmic generation. The phenomenal world and all its entities are constituted by their interactive synthesis, reflecting Chang’s holistic vision of reality as simultaneously dynamic and inherently meaningful.

4. Ch’i and Human Nature: Theoretical Foundations and Solutions to Mind-Nature Issue

Kasoff places metaphysical and cosmological Ch’i and its related concepts of “heaven and earth” in fundamental chapters. He argues that the four concepts of Ch’i, yin–yang, heaven, and spirit form the foundation of Chang Tsai’s theoretical system. Through the redefinition of the term Ch’i and its essential properties of yin and yang, Chang managed to “string it all on one thread”, providing an explanation for all elements within the cosmos under a single dominant principle. The concepts of Ch’i and yin–yang serve as the cornerstones of his perception of heaven and earth, and they supply the structure for his discourse on man. Kasoff expresses this as follows:

t (Chang’s system) had to explain all phenomena in the cosmos with one set of principles; it had to show that moral behavior was “natural”-consistent with human nature-while accounting for the presence of evil in the world; and it had to do all of these things so that there was a coherence and consistency among them

[1] (p. 125).

This fundamental understanding, according to Kasoff, empowered Chang to propose solutions to the issues that engaged the interest of many scholars during the eleventh century: (1) the essential components of human nature; and (2) whether this nature inherently embodies moral goodness or evil, and, if human nature is deemed good, what the origin of evil in the world is. He discovered that Chang’s theory of the unity of man and nature with Ch’i as its core does not primarily focus on the level of cosmogony or defining the ontological composition of nature in general. Instead, its most crucial aim lies in providing an ontological interpretation of the issues of mind and nature. As Chang made the point, man is one of the things of the world; thus, he is produced by the condensation of undifferentiated Ch’i as well.

Specifically, Kasoff expounds on how to understand Chang’s extension from the division of “the nature of heaven and earth 天地之性” and “the nature of the ch’i-constitution 气质之性” to the theory of human nature10. He believes that the following is true:

“void” refers to undifferentiated Ch’i; qi here refers to physical, condensed ch’i. The nature of undifferentiated Ch’i is the heaven-Nature, and of physical ch’i is the nature of the ch’i-constitution. It is only by including both of these that one arrives at a full understanding of “nature” in all its aspects

[1] (p. 76).

Chang’s theories of human nature align with Mencius’ doctrine, proposing that human nature inherently embodies moral goodness (shan, 善). However, Mencius—and by extension, Chang—argues that this innate ethical predisposition is often obscured by the encumbrances of human desires (yu, 欲) and affective responses (qing, 情). According to Kasoff’s interpretation, for Chang, even though the operations of heaven and earth happen spontaneously and without conscious intention, they are inherently good. They are characterized by productivity, nurturing capacity, dependability, and absolute impartiality. As a result, the yin–yang nature that presides over these operations is also good. All entities, whether living or non-living, that are made up of palpable ch’i preserve the perfectly good nature of the original Ch’i. This is what Chang referred to as the “nature of heaven and earth”, and it pervades every human being and everything. Human beings possess the inherent potential for moral goodness due to their shared nature with the ethical principles governing cosmic processes. The heavenly nature in human beings supplies Chang with a foundation on which to build a Confucian theory of human nature and ethical transformation [15] (p. 50). Nevertheless, when Ch’i condenses and acquires a physical form, it simultaneously takes on a nature that is an inherent part of that form. This nature, named by Chang as the “nature of the ch’i-constitution”, encompasses the fundamental instincts of physical beings and the unique features of each individual. When the desires that originate from physical nature are permitted to develop without restraint, greed and lust will ensue. Thus, the nature of the ch’i-constitution serves as the origin of evil in the world [1] (p. 66). Also, he proposed that Chang’s theories on human nature are in line with those of Mencius, who asserted that human nature is inherently good, yet this goodness is hindered by human desires and emotions. Alternatively, human beings possess both the latent capacity for goodness and a physical nature that might hinder the realization of that latent capacity. Whether or not an individual fulfills his potential hinges on his own endeavors; what is required for the realization of this potential is the process of learning. So far, the author believes that Chang’s theory of human nature has solved a fundamental problem in Chinese philosophy, which is how to subdue the evil ch’i nature through “learning” [1] (p. 76), thereby answering the question of why one should do what he/she does not want to do.

5. Ch’i and Sage: Human Existence, Self-Cultivation and the Ideal of Sagehood

By considering existence and constructing the metaphysical and physical aspects of Ch’i, Chang’s aim was not to investigate the rationale for existence but to argue for the value and significance of human existence. Chang Tsai’s formulation of self-cultivation as “exhausting one’s nature and knowing heaven 尽性知天” embodies a synthetic relationship between ontology and epistemology11 in his philosophy. He grounds human nature in the primordial Ch’i of the cosmos, such that “knowing heaven” is not an abstract cognitive act but a practical realization of one’s identity within the cosmic order. Kasoff’s analysis of “the sage” highlights how this transition occurs: by first apprehending the ontological unity of Ch’i, the sage engages in epistemological practices—such as “expanding the mind (jinxin, 尽心)” through ethical discipline and classical study—to actualize this understanding. In Chang’s system, epistemology is not a separate domain but the embodied process by which ontological truth is cognized and enacted, as the sage’s knowledge of heaven arises from aligning their conduct with the Ch’i-driven rhythms of the universe. By focusing on the concepts of “sage” and “mind”, he addresses Chang’s three key questions about what constitutes a sage (subject), what a sage does (function), and by what means a sage acts, thereby elucidating Chang’s ideal of human personality.

The sage is an individual who fully actualizes his human potential and completes his nature through the practice of expanding his mind. By broadening the scope of his understanding to encompass all phenomena within the cosmos, the sage apprehends the fundamental unity of all things: they are all formed by the condensation of the same undifferentiated Ch’i, and all processes and phenomena are governed by the cyclical interaction of yin–yang. This cosmic insight enables the sage to transcend egoistic concerns and perceive his physical existence as inherently continuous with the rest of reality. Kasoff explains Chang’s words of “Therefore that which fills the universe I regard as my body and that which directs the universe I consider as my Nature 故天地之塞吾其体, 天地之帅吾其性” in Western Inscription as follows:

What “fills the universe” is qi, which also forms “my body”; what “directs the universe” is the yin-yang polarity which is also “my Nature”. Because the sage has transcended the barrier between himself and others and is without self, he is void

[1] (p. 107) (Also see [16]).

For Chang, the most important benefit of learning lies in the transformation of the quality of Ch’i, and so the very first thing for learners is to transform their qi-quality [17] (p. 275). According to Kasoff, in Chang’s view, sagehood was the aim during the arduous process of learning. As he depicted, this process proceeds as follows: the learner first strives to modify and transform his ch’i-constitution to reach “This Mind (此心)”, which represents his intuitive capacity for understanding the Way. Then, he firmly anchors himself at this spot and “expands his mind” by applying this intuitive perception to more and more phenomena and circumstances until he grasps the ultimate unity of all things. To accomplish this is to complete his nature, that is, to become a sage. The underlying rationale is that, with both Ch’i and ch’i, human nature is essentially good but is veiled by temperament. Nevertheless, through learning, or rectifying the mind (zhengxin, 正心), which involves studying the classics and experiencing things with attention, one can overcome the temperament and attain the inherent ultimate goodness. The culmination of this process is what is termed “becoming a sage 成圣”, which is also in accordance with what Mencius stated, namely, everyone can become a Yao or Shun12 人皆可以为尧舜. According to Chang Tsai’s interpretation, this is the way of completing one’s nature and undergoing transformation 成性且化, casting aside impurities and conforming to heavenly principles. When a sage attains the state of “selflessness”, he becomes unified with all things in heaven and earth and then comprehends the principles of all things by applying the Way consistently. Subsequently, the sage can guide the world to understand and follow the heavenly Way, thereby bringing worldly affairs into order and fulfilling the goal of “initiating a peaceful world for all generations”. Kasoff’s elucidation clarifies that Chang Tsai founded the theory of the ideal of human life on the basis of his cosmology and theory of human nature. It is evident from this that Chang Tsai’s theory of Ch’i emphasized how human beings implement moral norms, how humans pursue and ascend in the human realm, and how to make human existence full of value and wisdom, thus endowing people with the spiritual need and capacity for upward pursuit.

So far, based on Kasoff’s interpretation, the Ch’i constitutes a structured ethical–rational structure, which is engendered through the hermeneutic engagement with Confucian canons and the logical progression of thought. With regard to the specific dimensions of Ch’i, at the level of individual personhood, it assumes the role of fostering moral cultivation; within the realm of ethical order, it contributes to the establishment of a salutary social ethos and the modulation of the interrelationship between humanity and the natural cosmos.

6. Contextualizing Distinctiveness by Contrasting Chang Tsai’s Ch’i-Based Ontology with Cheng-Zhu School

In the history of the transmission of the Confucian orthodoxy (daotong, 道统) as described by Zhu Xi, Zhou Dunyi (周敦颐) is established as the founding progenitor of Neo-Confucianism, whose teachings were first transmitted to the Cheng brothers and then to Chang Tsai and Shao Yong (邵雍). Notably, Chang—who was older than the Cheng brothers—appears in this lineage after them. Later philosophers largely adopted the views of the Cheng brothers’ disciples or Zhu Xi himself, positing that Chang’s thought originated from the Chengs or that Zhang studied under them. In The Thought of Chang Tsai (1020–1077), Kasoff challenges this tradition, offering a distinctive perspective that subverts conventional understandings through a meticulous examination of the relationship between Chang Tsai’s and Cheng brothers’ ideas.

As previously mentioned, Ch’i constitutes one of the principal categories in the annals of Chinese thought, permeating the history of Chinese thought throughout the ages. Since the Song Dynasty, the theories of Principle (Li, 理) and Ch’i, along with the theories of the Heavenly Way, have evolved into two entirely distinct “metaphysical” conceptions based on divergent stances in classical exegesis. One, represented by Zhu Xi, underscores how the metaphysical essence is Li, which is the root of all entities, being formless and imageless. The other, represented by Chang Tsai, Wang Tingxiang, Wu Tinghan, and others, emphasizes that the metaphysical essence is Ch’i, which is also the root of all things without a physical form. The emergence of Chang Tsai’s theory of Ch’i, in conjunction with Ira Kasoff’s interpretation, demonstrates that Ch’i has transmuted into the world’s primary substance in the Aristotelian sense, accompanied by the establishment of a cosmology founded on Ch’i. Kasoff’s demarcation renders the concept more refined, accentuating its primordial and pre-existent nature, its transformative and generative capacities, and its complexity and polysemy in practical applications. This demarcation makes the system more rigorous and comprehensive, facilitating a more accurate comprehension of Chang’s elucidation of the generative mechanism of all entities in the universe. It also enables the highlighting of the uniqueness of Chang’s thought when juxtaposed with other schools. For instance, Kasoff’s interpretation emphasizes that in the Correcting the Unenlightened: Taihe, Chang critiques Laozi’s assertion that “being emerges from non-being 有生于无”, arguing that positing the “Void” as the substance generating qi results in a fundamental severance between the infinite nature of the former and the finite nature of the latter, falling into the dilemma of “absolute separation between substance and function 体用殊绝”. He emphasizes that the Great Void is none other than qi, asserting that the “Void” is not absolute nothingness but the primordial state of qi in a dispersed, unaggregated condition. According to Kasoff, for Chang, being and non-being are merely different manifestations of the same substantial reality of qi—a unity he terms “the constant unity of being and non-being 有无混一常”. The cosmic generation, in his view, consists of qi’s own cyclical processes of aggregation and dispersion, rather than a creation of being from non-being. Chang thus criticizes Laozi for failing to recognize this constant principle of ontological non-duality—where substance and function, the void and concrete reality, are inherently unified and never truly separated.

Meanwhile, Cheng-Zhu school emphasizes the central position of Principle, or Li, in all things in the universe, whereas Chang Tsai constructs his philosophical system with Ch’i at its core. The Cheng-Zhu school argues Li as the metaphysical foundation of reality, asserting that every phenomenon adheres to a specific li, and all individual principles derive from a singular, universal Li. This Li dictates the normative roles within a harmonious society, where ethical conduct aligns with one’s prescribed social position. While improper behavior may follow a principle, it does not conform to the overarching Principle. In contrast, Chang Tsai conceptualized li as a ch’i-dependent property, denoting this unique pattern inherent to each entity. For Chang, ch’i condenses into specific forms according to these entity-specific li, but he rejected the Cheng-Zhu notion of a monolithic Li subsuming all particular principles. Kasoff highlights this divergence: “For Chang Tsai, Li are the patterns inherent in the transformations of ch’i, not metaphysical entities governing them” [1] (p. 135). Chang’s cosmology integrates Great Void as ch’i’s undifferentiated state and yin–yang as its generative forces, rejecting the Cheng view of ch’i as a derivative of Li. As mentioned previously, the Great Void—Ch’i’s undifferentiated, generative state—anchors this ontology, grounding ethics in humanity’s inherent connection to cosmic processes. This contrasts with Cheng-Zhu School’s Li-centric ontology, prioritizing material–processual unity over transcendent norms. In cosmic generation, Chang emphasizes spontaneous condensation and the dispersal of ch’i guided by yin–yang interactions, whereas the Cheng-Zhu school attributes generation to Li’s self-expression through ch’i. Chang roots morality in Great Void’s ethical potential, actualized through ch’i’s cultivation, in contrast to the Cheng brothers’ dualistic separation of transcendent Li (ethical) and material ch’i. Kasoff concludes that Chang’s synthesis of ch’i’s dynamic materiality with yin–yang ethics offers a holistic, process-oriented vision challenging the static, normativistic metaphysics Cheng-Zhu [1] (pp. 37–42). This reorientation grounds Neo-Confucian ethics in cosmic materiality, reshaping the tradition’s ontological and ethical discourse. Thus, Kasoff concludes the following: “The fact that Chang’s philosophy became absorbed into the Ch’eng school has obscured that fact that Chang was an independent thinker, one of the founding fathers of Neo-Confucianism” [1] (p. 147).

7. Conclusions

Ira Kasoff’s work, exploring Chang Tsai’s philosophy and following the analytical method of philosophical concepts [18] (p. 54), constructs a well-crafted philosophical framework centered around Ch’i. As he puts states, “in adopting this approach I have made certain assumptions. The first, like Chang Tsai’s assumption about the Classics, is that there is one “Way” described in the various works and in different parts of the same work. That is, I assume first that Chang’s writings embody a systematic, consistent philosophy; and second, that we can piece this philosophy together from the extant texts [1]” (p. xii).

Kasoff’s interpretation of Chang Tsai’s philosophy makes contributions to both Chinese and English-language scholarship by systematically reconstructing Chang’s Ch’i-centered cosmology while providing a more nuanced lens for Western Neo-Confucian studies. Unlike prior translations that rendered qi monolithically as material force or vital power, Kasoff’s trichotomous framework captures Chang’s ontology. This approach resolves inconsistencies in prior interpretations, clarifying how Chang unifies different realms through qi’s cyclical transformations, thereby refuting Buddhist illusionism (i.e., his critique of Kong 空) and Daoist non-being. Kasoff further diverges from Cheng-Zhu scholarship by foregrounding qi as the foundation of ethics and cosmology, contrasting with the Cheng brothers’ and Zhu Xi’s prioritization of Li. His analysis emphasizes Chang’s integration of human nature and sagehood into qi’s dynamics, arguing that moral cultivation hinges on aligning individual ch’i with cosmic Ch’i—a synthesis overlooked in earlier fragmented studies. By contextualizing Chang’s thought within 11th-century debates and leveraging insights from Zhang Dainian, Kasoff bridges Chinese exegetical traditions with Western philosophical rigor, offering a cohesive framework that positions Chang as an independent Neo-Confucian pioneer rather than a mere precursor to Cheng-Zhu orthodoxy. It establishes qi as a dynamic, ethically charged concept central to understanding Neo-Confucianism’s materialist underpinnings. Yet Kasoff’s work also invites further inquiry. While his trichotomy clarifies Ch’i’s ontological layers, it risks reifying terminological distinctions in Chang’s fluid texts13, and its contextual-based approach could prove insufficient for providing a thorough understanding from a historian’s perspective [19]. Future research should interrogate how Chang’s Ch’i-ontology accommodates both continuity and discontinuity, or explore its ecological implications, as an under-explored dimension of Kasoff’s analysis.