Flesh, Vital Energy and Illness: A Comparative Phenomenological Study of Human–Nature Relations Inspired by the Contexts of Later Merleau-Ponty and the Zhuangzi

: The main aim of this paper is to illustrate human–nature relations from a comparative study of the contexts of later Merleau-Ponty and the Zhuangzi . I argue that the Zhuangzi has its own phenomenology of the natural world, which is worth comparing to Merleau-Pontian later phenomenology. To compare the arguments on human–nature relations in the contexts of later Merleau-Ponty and the Zhuangzi in detail, ﬁrst, I brieﬂy compare the cultural philosophies of nature in ancient Greece and China and their possible inﬂuences on our contemporary understanding of nature. Second, I compare the concept of “ﬂesh” of Merleau-Ponty with the concept of “vital energy” in the Zhuangzi and point out the main roles of these concepts in their respective theories of the natural world. Third, I use the “reversibility thesis” created by Merleau-Ponty to analyze the ontological signiﬁcance of illness in the arguments of Merleau-Ponty and the Zhuangzi . Fourth, inspired by Merleau-Pontian and Zhuangzian ideas about language and expression, I expound on a view of illness as a primordial language of nature and its possible role in mediating human–nature relations. Ultimately, I conclude that the comparative study of thoughts on human–nature relations in the literatures of later Merleau-Ponty and the Zhuangzi can help us reconsider and readjust our main attitudes toward nature, illness and nonhuman beings in the contemporary postpandemic era.


Introduction
The 2020 global outbreak of the COVID-19 pandemic has given people an opportunity to reconsider the relationship between human-nature relations. If we admit that the pandemic is a warning message from nature (Weckert 2020), then the endless tragedies happening around the world amply illustrate the terrible power of nature and the helplessness of humans. As of 1 July 2022, the World Health Organization (WHO) reports that there have been 545,226,550 confirmed cases of COVID-19 worldwide, including 6,334,728 deaths. 1 For today's postpandemic context, we adopt an ambivalent dual attitude towards nature. On the one hand, we have a very intimate relationship with nature because of the endless supplies of food and energy obtained from it; on the other hand, however, we often have tension with it because illnesses, viruses, earthquakes, tsunamis and floods are all natural catastrophes that cause irreversible effects on human beings. This ambivalent dual attitude leaves big questions unanswered about the humannature relations. That is, how can the status of humans in nature be reoriented in the postpandemic era? If humans still act as masters of nature, how could nature affect their bodies and determine their fates? Could illness be seen as any ontological status in nature? How does illness adjust human-nature relations?
Such questions seem quite difficult to answer. Nevertheless, if we admit that the pandemic gives us a new chance to reflect philosophically on ourselves and our relationship to nature (Carel 2014), Merleau-Pontian and Zhuangzian approaches to nature would give us a great deal of enlightenment to reconsider human-nature relations. This paper's main concern is reflecting on our relations to nature in a comparative phenomenological way, especially by investigating the ontological roles of illness in the philosophical contexts of the thought of later Merleau-Ponty and the Zhuangzi. To compare the arguments on human-nature relations in the literatures of later Merleau-Ponty and the Zhuangzi in detail, I first compare views on nature from ancient Greece and China and their possible influences on our contemporary views of nature. Then, I compare Merleau-Ponty's concept of "flesh" with the concept of "vital energy" in the Zhuangzi, and use the "reversibility thesis" created by Merleau-Ponty to analyze the ontological significance of illness inspired by the literatures of later Merleau-Ponty and the Zhuangzi. I argue that illness can be seen as a mechanism of "reversibility" which mediates the subjective-objective relations between humans and nature. Illness also acts as a sort of primordial "language" by which it expresses the appeals of nature and accomplishes a series of reversible relations between subjectivity and objectivity, perceiving and being perceived, and life and death, as well as equalizing humans and nonhumans in interactional and coexisting senses.

Modern and Ancient Nature Views and the "Discovery of Nature"
The modern view of nature originated from the rise and change of science and technology since the period of the Scientific Revolution. Nature then has gradually become the cognitive target of human reason and the actual object of technological transformation. The modern concept of "nature" means a "collection" of nature objects or nature things (Collingwood 1945). According to John S. Mill, the concept of nature has a twofold meaning: "In the first meaning, "Nature" is a collective name for everything that exists or happens. In the second meaning, "Nature" is a name for everything that exists or happens without voluntary human intervention" (Mill 2017, p. 4).
It is in Mill's sense that nature signifies a sort of collective thing that appears to us, and before the birth of human beings, nature has always already existed for a long time. Furthermore, Mill argues that the concept of "nature" does not have a third meaning, i.e., a meaning in an ethical sense, because nature reveals the actual world as it is rather than a moral world as it ought to be (Mill 2017, p. 4). Accordingly, as Mill explains, nature cannot be an ethical standard for us to imitate because nature per se is irrational and immoral. Nature's "plague and cholera far surpass the poison cups of the Borgias" (Mill 2017, p. 11). In other words, nature's spontaneous course has nothing to do with kindness, and the duty of humans is to amend and remold nature with their own interests.
Mill's idea about nature is very representative of the modern view that people always treat nature as merely means without its own ends, and this sort of valueless and unfeeling nature can be seen as the root cause of the environmental issues of modernity.
Despite the modern understanding that treats nature as a "collection" of things, there also exists an ancient understanding that regards nature as a "principle" or "source." According to Collingwood, the latter meaning of nature is the original or proper meaning in the ancient times of Greece and Rome (Collingwood 1945, p. 43). In Greek and Latin, respectively, Φυσις and Natura refer to the root cause of what makes things the way they are. For example, we usually say that the nature of an oak is to be tough, and the nature of ash is to be pliant. Thus, nature for the ancient Greeks is not something made of objective, inert materials but a subjective and living organism. Humans, as members of nature, are themselves in accordance with the intrinsic purpose (which modern people often call "natural law") of nature per se. Nature as a whole is not only vital but also divine. Accordingly, humans can only follow nature and imitate nature rather than transform nature or govern nature.
However, humans' inability to thoroughly develop and transform nature does not mean that we cannot investigate it. For ancient Greeks, "the world of nature is a world not only of ceaseless motion and therefore alive, but also a world of orderly or regular motion" (Collingwood 1945, p. 3). Thus, the orders or rules of nature need human reason (i.e., logos) in order to be studied and explored. It is in this sense that, as G. E. R. Lloyd puts it, the ancient Greeks made a "discovery of nature" for the first time in the history of science (Lloyd 1970, p. 8). What Lloyd means is that the natural philosophers of ancient Greece first distinguish natural from supernatural, regarding the former as a domain of cause and effect, thus expelling the latter from the former (see Lloyd 1970, p. 8). Through the "discovery of nature", humans can use their own rational ability to discover the laws of nature.
Nevertheless, what is paradoxical is that if humans can use their rational ability to discover nature, it signifies that nature becomes an object of human reason, and humans are inevitably bound to separate themselves from nature. This, in turn, fits in Mill's argument on nature. That is to say, on the one hand, humans are parts of nature, and on the other hand, it can be investigated by rational abilities and gradually become an objective target of human reason. From my point of view, this twofold situation reveals the inner tension in the view of nature of the ancient Greeks. Precisely because of this tension, it prepares a way for modern science to treat Greek natural philosophy as its origin of thought. 2 If the "discovery of nature" is the premise of the human rational understanding of the world, the potential logical consequence is to bring about a series of binary oppositions, such as humans and nature, selves and others, minds and bodies. The reason is that when we objectify nature by our rational abilities, humans and nature are inevitably separated from each other, nature becomes an inert object to be conquered by human reason. Additionally, with the help of rational abilities of humans, science and technology become the most effective tools for subjective humans to transform objective nature. Thus, the Cartesian manifesto "I think, therefore I am" not only claimed the triumph of human reason, but the potential consequences were to establish a series of binary oppositions.
Therefore, the questions that arise are as follows: How can the theoretical model of the duality of humans and nature be broken up? Is it possible to construct a natural philosophy in which humans and nature are in symbiosis? How can the eastern philosophical tradition inspire us to overcome the dual paradigm within western philosophy?

The Incarnated Nature in Classical Chinese Views of Nature
Unlike the ancient Greeks' "discovery of nature" and the modern nature views, which treat nature as an objective system of natural law that can be recognized by human reason and as an objective substance that can be transformed by science and technology, ancient Chinese philosophers and litterateurs regard nature as a subjective and affective entity which can influence the integrity, moral traits and emotional feelings of humans. That is to say, in classical Chinese natural philosophy, nature and humans are a harmonious and symbiotic unity, and the interaction between humans and nature is reflected in a certain of moral and emotional connection. For example, plum blossoms, orchids, bamboos, and chrysanthemums are described as the "four gentlemen" because the Chinese believe that these four plants represent the noble virtues of humans (Hui 2009). Plants, mountains, rivers, animals and natural phenomena are basic images in ancient Chinese poetry and arts. 3 Thus, we can generally argue that in classical Chinese natural philosophy, nature is emerged by a sentimental connection with humans, rather than recognized by human reason or transformed by science and technology.
Obviously, nature as a sentimental subject can not only respond to someone's emotional feelings but also invite someone into certain mental states. This sort of affinitive and mutual relation between nature and humans can be described as the term "Heaven-Human Oneness" (tian ren he yi/天人合一) or "mutual perception between Heaven and Human" (tian ren gan ying/天人感應). 4 For instance, during the Wei and Jin Dynasties (220-420), the political failures and social outliers become recluses; they often indulge in mountains and rivers, thereby keeping distance from the dirty affairs of humankind and cultivating their virtuous character in nature. 5 From a phenomenological point of view, nature in ancient Chinese philosophy and literature can be regarded as an incarnated, subjective, and sentimental being; it is a vital part of human life, and human life is also a vital part of nature. Nature gives people emotional sustenance, provokes mental states and acts as the origins of human virtue. Unlike the ancient Greeks, nature for the ancient Chinese is more of a carrier of sentiment rather than a principle of rationality. 6 Therefore, the relation between nature and humans in a primordial or prereflective sense is in oneness.

Merleau-Ponty on the Flesh, Nature and Their Relation of "Chiasm"
Similar to the ancient Chinese views on nature, the French phenomenologist Maurice Merleau-Ponty also mentions a philosophy of nature in terms of his phenomenology of the body. In the Phenomenology of Perception (PhP), Merleau-Ponty reveals that the body plays a mediating role between humans and the world, thereby actively constituting our being-in-the-world (Merleau-Ponty 2012, pp. 147-48). Meanwhile, this sort of body can be seen as a "measurement" by which things are regulated and adjusted, and this "measuring body" actively mediates the subjectivity of humans and the objectivity of the world (Hoel and Carusi 2018). That is, "I am my body", the body is always a "lived body" that can be seen as a source of our lifeworld rather than a passive physical entity that may increase our living burdens. It is in this sense that the "lived body" or so-called "phenomenal body" surpasses the passive body or so-called "objective body" (Merleau-Ponty 2012, p. 108).
Of course, nature is not the theme in PhP, and in contrast to my lived body, the body of others (including humans and nonhumans) and all of nature still seems passive and objective. 7 That is, the phenomenology of the body in PhP still presupposes a dualism between selves and others, humans and nature. Thus, it is an incomplete break with Cartesian mind-body dualism. Merleau-Ponty himself also notices this theoretical flaw; in his later work, Visible and Invisible (VI), he claims that "The problems posed in PhP are insoluble because I start there from the 'consciousness'-'object' distinction" (Merleau-Ponty 1968, p. 200).
According to Merleau-Ponty, now that the dualism is still insoluble in an epistemological sense, it is necessary to establish a new ontology that treats selves and others and humans and nature in a unified way. This unified way is the main theme in his later works.
In VI, Merleau-Ponty launches a new ontology of the world, that is, the world constituted by "flesh" (chair). The "flesh" signifies a general element "midway between the spatiotemporal individual and the idea"; it acts as an "incarnate principle" that entails the existence of the world, and humans and nonhumans intertwine with each other (Merleau-Ponty 1968, p. 139). 8 In other words, the "flesh" can be seen as a primordial foundation for our "lived bodies", nonhuman bodies and the world.
For Merleau-Ponty, neither is the world something "outside" of our "lived bodies" nor are our "lived bodies" something "inside" of the world. In fact, the relation between humans, nonhumans and the world is a relation of "chiasm" rather than a relation of mutual externality. The term "chiasm" implies a prereflective and primordial link between all beings, i.e., an intercorporeality between humans, nonhumans and the world. It is also in this sense that, according to Todavine, the term "chiasm" opens up a new understanding of human-nature relations (Todavine 2009, p. 107).
As I see things, in light of the concepts of "flesh" and "chiasm", a new ontology opens up, entailing a "sympathy" between selves, others and nature. In Eye and Mind, Merleau-Ponty compares the "flesh" to a mirror (Merleau-Ponty 1993, pp. 129-30). A mirror reflects the images of myself and others. I recognize myself and others in the mirror images, and both myself and others are in a circuit of mutual reflection. Thus, "man is a mirror for man. Mirrors are instruments of a universal magic that converts things into spectacle, spectacle into things, myself into another, and another into myself" (Merleau-Ponty 1993, p. 130). Consequently, I can feel other's feelings, just like other people can also feel my feelings. Likewise, I can feel nature just like nature can also feel me. Because humans, nonhumans and nature are constituted by the same "flesh" of being, they intertwine with each other in a primordial sense, or one could say they are in "oneness" (or in "chiasm") from a pure intercorporeal perspective.
If my understanding of Merleau-Ponty's later works is correct, nature, as with our "lived bodies", is a reversible being that can both perceive and be perceived. Merleau-Ponty reveals that the body is a "two-dimensional being" that can both touch and be touched, see and be seen. The body unites the properties of "subject" and "object" within itself (Merleau-Ponty 1968, p. 137). For Merleau-Ponty, this double condition is called the "reversibility of the body." According to Aarø (2010), this sort of "reversibility thesis" carries our understanding of nature as well. In Nature: Course Notes from the college de France (Nature), Merleau-Ponty underlines that: Nature is the primordial-that is, the nonconstructed, the noninstituted; . . . Nature is an enigmatic object, an object that is not an object at all; it is not truly set out in front of us. It is our soil [sol]-not what is in front of us, facing us, but rather, that which carries us. (Merleau-Ponty 2003, p. 4) Nature is neither an object that is recognized and transformed by humans nor is it merely a material collection. Rather, nature is the primordial and essential foundation of our being-in-the-world. Nature thus carries humans and provides us with the original significance of existence. Similar to our body being "an ambiguous organization where the two hands can alternate between the functions of 'touching' and being 'touched,'" (Merleau-Ponty 2012, p. 95), nature can also be seen as "a two-dimensional being" or "an ambiguous organization" in which it can alternate between objectivity and subjectivity; nature is capable of both perceiving and being perceived, and it entails both objective and subjective properties. Thus, for Merleau-Ponty, nature is "a leaf or layer of total Being", and it is "the expression of an ontology" (Merleau-Ponty 2003, p. 204). The purpose of Merleau-Ponty's phenomenology of nature is "neither simple reflection on the immanent rules of the science of Nature, nor recourse to Nature as to one separated and explanatory Being, but rather explication of what being-natural or being naturally means" (Merleau-Ponty 2003, p. 206). Therefore, nature is a domain associated with "primordial Being" rather than an objective domain separate from humans. According to this understanding of nature, whether humans, animals, plants, or inanimate beings, all have "equal" status on an ontological level. There is no binary distinction or hierarchy between humans and nature.
It is in the above sense that nature represents an intertwining relation between humanity, animality and nature. Humanity is a side of nature, just as animality is another side. Therefore, nature reverses from one side to another side and back again. The reversibility mechanism of nature ensures that our bodies, other bodies, and bodies of nonhumans can feel sympathy or Einfühlung with each other because they are all in a circuit of the "flesh" of nature.

When Merleau-Ponty Encounters Zhuangzi: "Flesh" of the World and All Things in the "Vital Energy" (氣)
Similarly, in the book Zhuangzi 9 , which is a classical literature of philosophical Daoism, also mentions a sort of philosophy of nature that is worth comparing with the Merleau-Pontian phenomenology of nature. Some Chinese scholars from Taiwan suggest that the Zhuangzi actually establishes a phenomenology of "vital energy", and this concept is very similar to the concept of "flesh", which Merleau-Ponty mentions in his later work, VI (see Chung 2013Chung , 2014Chan 2021).
According to the Zhuangzi, "vital energy" (qi/氣) 10 is a fundamental element that permeates our "lived bodies" and all of nature. When Zhuangzi's wife died, he explained to Huizi惠子about the principles of life from birth to death: Amid what was opaque and obscure, transformation took place, and she obtained her vital energy. Another transformation took place with her vital energy, and she obtained her physical form. Yet another transformation took place with her physical form, and she obtained life. Now that one more transformation has taken place and she has returned to death, this is like the succession of spring, summer, autumn and winter 雜乎芒芴之 間,變而有氣,氣變而有形,形變而有生,今又變而之死,是相與為春秋冬夏四時行 也. (Zhuangzi 1999, p. 289) Here, "vital energy", as with "flesh", plays an ontological role through which the physical form (i.e., the Körper in the phenomenological sense) emerged, and then life (i.e., the Leib or the "lived body" in the phenomenological sense) was born. Thus, in the Zhuangzi, human lives are in the circuit of "vital energy", just as the changes in the seasons are contained in the generation and transformation of "vital energy." In the chapter of "knowledge travels north", 知北遊 the Yellow Emperor argues that "All things in the world are in the same circle of life and death. . . . So, it is said, 'Everything in the world is attributed to the same vital energy'". 故萬物一也 . . . 故曰: '通天下一氣耳' (Zhuangzi 1999, p. 363).
Obviously, "vital energy" is an incarnated or embodied ontological being. 11 It is a primordial being of all things, including humans and nonhumans, and it constitutes our living context and guarantees all beings and things are equal and unified into oneness. As Zhuangzi argues in the "inner chapter" of "on the uniformity of all thing" 齊物論: "The heaven and the earth and I came into existence at the same time; all things in the world and I are one uniformity" 天地與我並生, 而萬物與我為一 (Zhuangzi 1999, p. 29).
Furthermore, "vital energy", as with "flesh", is a "two dimensional being" both visible and invisible. It acts as a fluid element flowing from one entity into another entity and from one situation into another situation. In the Zhuangzi, "vital energy" represents an invisible principle of nature (i.e., the Dao) that makes everything visible:"[D]ao is a reality which has its substance, inert and formless. It can be acquired by the heart, but not seen by the eyes" 夫道, 有情有信, 無為無形; 可傳而不可受, 可得 而不可見 (Zhuangzi 1999, p. 95). The "vital energy" of nature can be absorbed into humans' own bodies and influences and constitutes their moods and characters; likewise, "vital energy" from one person can also influence his or her own "atmosphere" nearby and even be transmitted to the environment and to other persons. For example, the Zhuangzi mentions the "true man" who obtains the Dao by cultivating his body, and his "joy and anger succeeded each other as naturally as the succession of the four seasons. He was in conformity with everything in the world" 喜怒通四時, 與 物有宜而莫知其極 (Zhuangzi 1999, p. 91).Thus, in both the literatures of Zhuangzi and later Merleau-Ponty, humans and nature intertwine and influence each other, and we cannot think separately about our bodies without the natural contexts in which the bodies dwell. Meanwhile, we cannot think separately about nature without the incarnate or embodied contexts in which nature dwells.

The Role of Illness in the "Reversibility Thesis"
According to the above analysis, we can see that for both Merleau-Ponty and the Zhuangzi, nature is an incarnated domain that is both perceiving and being perceived, visible and invisible, and objective and subjective. This "two-dimensional being" of nature fully demonstrates the significance of the "reversibility thesis" launched and developed by Merleau-Ponty. As I mentioned above, in VI, the body is both touching and being touched. However, this "double sensation" is noncoincident; i.e., touch-ing and being touched can only appear alternately rather than simultaneously. As Merleau-Ponty argues: My left hand is always on the verge of touching my right hand touching the things, but I never reach coincidence; the coincidence eclipses at the moment of realization, and one of two things always occurs: either my right hand really passes over to the rank of touched, but then its hold on the world is interrupted; or it retains its hold on the world, but then I do not really touch it-my right hand touching, I palpate with my left hand only its outer covering. (Merleau-Ponty 1968, pp. 147-48) That is, due to the noncoincidence of "double sensation", according to Daly, the awareness of this noncoincidence occurs at the level of reflection (Daly 2016, p. 67). In other words, because of the gap or break between touching and being touched, the significance of reflection is generated. Thus, the body is thematized and becomes an object that lets us investigate it. Otherwise, the body is just in a level of prereflection, and the primordial meaning of the body cannot be revealed by our consciousness. Only by transforming the body from a primordial level into a reflective level can the primordial and reversible significance of the body be uncovered.
Nevertheless, the question remains: Why would the body inevitably switch from a subjective state to an objective one or from being invisible to visible? From my point of view, if the body shares the same element (i.e., "flesh") with nature, then illness can be seen as an ontological precondition of this sort of reversibility. That is, if we admit that illness derives from nature, then it can be regarded as a common fate of our beingin-the-world. According to Leder (1990), only when we are sick does the meaning of the body become apparent. In other words, only when the body is in a state of illness does the body switch from being absent to being present. Accordingly, the "reversibility of the body" is actually a phenomenon derived from nature; this quality of reversibility effectuates the transformation from normality (for example, health) to abnormality (for example, illness) and from absent to present.
According to the Zhuangzi, illness derives from the incompatibility of "vital energy", i.e., the disharmonious relation between "yin"陰 and "yang"陽. 12 For example, in the Zhuangzi, a patient called Ziyu子輿 was described as ill, because the "vital breaths of yin and yang in his body were out of balance" 陰陽之氣有沴 (Zhuangzi 1999, p. 101). Here, the Zhuangzi gives an ontological pathogenesis of illness and opens up a way to perceive the reversible relation between the health and illness of our bodies. Thus, not only health and illness but also life and death are all in the circuit of "vital energy": "Life is the successor to death, and death is the beginning of life. . . . The birth of a man is the convergence of vital energy, which in turn forms life. The dissociation of the vital energy causes death" 生也死之徒, 死也生之始, . . . 人之生, 氣之聚 也; 聚則為生, 散則為死 (Zhuangzi 1999, p. 363). Then, if we continue this Zhuangzian train of thought, it is apparent that illness is midway between life and death; the consequence of illness is death, and the precondition of illness is health, while the beginning point of this circuit is birth into life. Therefore, it is precisely because the noncoincidence of life and death causes illness that illness is both the precondition and the outcome of the reversible relation between life and death. Hence, we can see that illness "awakens" and explicates the meaning of the body, the meaning of life and death, and the meaning of our relation with nature. Illness, in the above sense, can be regarded as the genesis of our self-reflection.
Moreover, I argue that illness prominently represents the intercorporal relation between humans, nonhumans and the world. For Merleau-Ponty, the structure of sympathy or Einfühlung is highlighted in the state of illness, and humanity, animality and materiality are all in a circuit of Einfühlung constituted by "flesh" or "vital energy". As Merleau-Ponty reveals, "my body [is] standing in front of the upright things, in a circuit with the world, an Einfühlung with the world, with the things, with the animals, with other bodies made comprehensible by this theory of flesh" (Merleau-Ponty 2003, p. 209). Thus, as Dahiya (2020) argues, illness, especially the current COVID-19 pandemic, makes us confront our experiences of touching and being touched. Due to this reversible experience of touching and being touched in our relationships with others in the special context of the pandemic, we finally realize how perceptions (for example, tactile sense) establish our positive or negative interrelations with others and even the entire world.
If illness can be regarded as the genesis of our self-reflection, and it accomplishes a sort of reversibility between humans and nonhumans, then we begin to wonder: What kind of role does illness play in nature? How does illness affect and even determine the mutual relations between humans and nonhumans? Can we treat illness as a logos of nature? Can illness "speak" to us without any vocal words? Moreover, how might Merleau-Ponty and the Zhuangzi regard illness in their ontological frameworks? To answer these questions, we need to retrospectively review Merleau-Pontian and Zhuangzian arguments on the primordial language of nature.

Merleau-Ponty and the Zhuangzi on the Language of Nature
In VI, Merleau-Ponty analyzes the primordial aspect of language and identifies that language "is everything, since it is a noise of no one, since it is a very voice of the things, the waves, and the forests" (Merleau-Ponty 1968, p. 155). Obviously, for Merleau-Ponty, the primordial aspect of language is a wild condition of nature. All vocal and rational languages are constituted by and founded on this primordial language of nature. In other words, the logos of nature is already throughout everything in the world before any instituted and constructed voices, so it is not so much that we speak language as that language "speaks" us. As Merleau-Ponty writes, "It speaks in us rather than that we do speak it" (Merleau-Ponty 2003, p. 212). Thus, the primordial language of nature is not a transcendent logos that is specialized by human beings but rather a ubiquitous logos contained in all sorts of beings, including humanity, animality and even nonliving beings. The nature of language is "the silent communication of perception"; any rational and instituted language is found in a nature that can be perceived with the senses and derives from that self-same sensible nature. As Merleau-Ponty argues in Nature, "The origin of language is mythic; that is, there is always a language before language, which is perception" (Merleau-Ponty 2003, p. 219).
Coincidently, the primordial and ubiquitous logos of nature that Merleau-Ponty reveals is similar to the Dao道 in the Zhuangzi; in Greek and Chinese, logos and Dao both contain the meaning of speech. In the Zhuangzi, the Dao is everywhere and covers every being-even excrement is also governed by the Dao (Zhuangzi 1999, p. 373)and the Dao is tacit and cannot be spoken by any rational words. The Dao is unsayable, as "those who know never say and those who say never know. Therefore, the perfect man teaches without words" 夫知者不言, 言者不知, 故聖人行不言之教 (Zhuangzi 1999, p. 363).
However, there exists a primordial sense of speech, according to Eske Møllgaard's analysis of Zhuangzian philosophy of language, that speech "self-emerges and flourishes spontaneously like all phenomena of nature" (Møllgaard 2007, p. 69). In the Zhuangzi, the authentic or primordial language is exposed between Heaven and Man, and this sort of language opens up an opportunity for a pure relation with the world. Thus, the authentic meaning of nature is unsayable and silent; nature is not directly spoken to us but rather conveys its secrets by ways of being perceived. Only by exchanging vital energies between nature and humans can we perceive nature and understand the Dao in nature.
Apparently, both in the contexts of later Merleau-Ponty and the Zhuangzi, the language of nature is silent, tacit and primordial, and the main function of this sort of asonant language is to reveal the primordial being. As Heidegger implies, the essence of language, as with the essence of art, is the aletheia of being (Heidegger 1971, pp. 35, 57). Merleau-Ponty reveals that the origin of language is a tacit perception, and the language of nature actually conveys a circuit between perceiving and being perceived, visible and invisible, vocal and voiceless, etc. While in the Zhuangzi, the language of nature is the unsayable Dao, the best way to obtain the Dao and understand the language of nature is to perceive nature and intertwine with nature into oneness, and the language of nature also reveals a circuit between life and death, virtual energies and physical forms, sayable and unsayable, and so on.

Illness as a Language of Nature
Both in the literatures of later Merleau-Ponty and the Zhuangzi, language brings out the significance of our being-in-the-world, and the language of nature reveals our primordial senses of nature and asks us to reconsider the mutual relation between humans and nature. Language is thus actually located midway between humans and nature; it uncovers the "ultimate truth" of nature and our relations with it. Illness can be seen as a similar language that conveys the silent message from nature to humans, and vice versa. Illness, as a language of nature, accomplishes a circuit between subjectivity and objectivity, perceiving and being perceived, and life and death, as well as equalizing all living and nonliving beings in interactional and coexisting senses.
First, illness, as a fundamental language of nature, can be regarded as a subjectiveobjective reversible mechanism between humans and nature. As I have mentioned above, illness is as old as nature, and it implies a significance of primordial being. On the one hand, illness reduces our bodies, as if they are no longer the source and essence of our subjectivity per se, but objects that are out of our own control. On the other hand, illness actually activates the subjectivity of nature as nature acts on the bodies of humankind; in other words, nature objectifies humans through illness. For example, when humans are quarantined at home because of the pandemic, the subjectivity of nature is awakened, the rivers and air become naturally clearer, the boundary of the forests extends into the city center, and wild animals roam the deserted streets. Humans become objects in contrast to the subjectivity of nature, i.e., humans are imprisoned by the forces of nature: they need to cancel all social activities, stay at home and keep socially distancing from other humans and other beings in nature. Therefore, illness, as one of the tacit and primordial languages of nature, reveals the reversibility of nature and humans, as between subjectivity and objectivity.
Second, illness transforms the attributes of perceiving and being perceived. If illness is a language of nature, nature can be logically regarded as an entity that is able to speak and perceive, and then nature can be seen as a living organism. Meanwhile, humans lose their perceptivity when they get sick and become the inert entities that humans' own sensory abilities are "deprived" by nature. For example, when we get COVID-19, our senses of taste and smell are stripped by the virus, as if our senses have been stripped away by nature and our bodies become quasi-objects. Thus, humans' sensory abilities are actually derived from nature; they exist merely as an extension of the sensory abilities of nature, and illness causes humans to switch between perceiving and being perceived.
Third, illness accomplishes a reversibility of all natural living beings between life and death. As I have mentioned above, illness opens up a way to death, and it apparently reveals the significance of the upcoming death. In fact, as Kierkegaard argues, we are both healthy and sick, rather than either healthy or sick (Kierkegaard 1980, p. 23). This paradoxical and dialectical condition is the destiny of almost all living beings in nature. Thus, illness as a primordial language of nature constantly "speaks" to us about the significances of life and death; illness can then be regarded as the source of meaning of our existence.
Fourth, illness signifies a certain reciprocity between humans and nonhumans, thereby equalizing humans and nonhumans at an ontological level. For example, the coronavirus can be seen as the "word" or message that nature "speaks" to us; it can not only transmit from humans to humans but also from animals to humans. It is in this sense that illness is a common "language" of humans and nonhumans in nature. Humans and nonhumans are all in a circuit from which all beings are equal and reciprocal to each other in an ontological sense.

Concluding Remarks
This paper illustrates human-nature relations from the comparative contexts of later Merleau-Ponty and the Zhuangzi. The main logical points of this paper can be summarized as follows: 1.
I briefly discuss the views of nature from ancient Greece and China and their possible influences on contemporary views of nature. 2. I compare Merleau-Ponty's phenomenology of "flesh" with the theory of "vital energy" in the Zhuangzi and then reveal the commonalities of human-nature relations in the literatures of later Merleau-Ponty and the Zhuangzi. 3. I analyze the "reversibility thesis" pointed out by Merleau-Ponty, thereby discussing the role of illness in the reversible relations between humans and nature. 4. I expound on the main ideas of language and expression that Merleau-Ponty and the Zhuangzi have pointed out, thereby arguing that illness can be seen as a sort of primordial language derived from nature. 5. I sequentially analyze the ontological roles of illness in human-nature relations, and I argue that illness as a sort of language of nature accomplishes a circuit between subjectivity and objectivity, perceiving and being perceived, and life and death, as well as equalizing humans and nonhumans in interactional and coexisting senses. Accordingly, nature is not an independent entity but rather as a domain of primordial being in which humans and nonhumans intertwine with each other. In fact, every being in the world is in a corporeal circuit between subjectivity and objectivity, perceiving and being perceived, life and death, and health and illness. These paradoxical conditions have profoundly revealed our fates in nature. That is, we cannot annihilate one being and replenish another being but rather must coordinate the relationships between the two beings dynamically. Merleau-Pontian and Zhuangzian philosophical wisdom can greatly inspire us. Just as humans and nature intertwine with each other, the ultimate truths from the East and West intertwine and resonate with each other. Just as nature was first discovered by the ancient Greeks from a sense of logos, this moment of dynamic transition in subjectivity is an occasion for us to rediscover nature from a primordial or prereflective sense, thereby readjusting our main attitudes toward nature, illness and nonhumans in the contemporary postpandemic era. As Engels argues in Dialectics of Nature: "Theoretical natural science is therefore likewise forced to go back to the Greeks if it desires to trace the history of the origin and development of the general principles it holds today" (Engels 1987, p. 342) 3 The images of nature run through the whole history of Chinese literature. For example, there are plenty of natural images in The Book of Songs (Shi Jing), the earliest collection of poems, compiled between the early Zhou Dynasty and the middle of the Spring and Autumn Period (11th to 6th centuries BC). For the role of nature in ancient Chinese poetry, see Mark Elvin (2004, pp. 321-68). 4 In Chinese culture, we refer to nature in terms of "Heaven" (tian) and "Earth" (di). "Heaven" and "Earth" can be seen as sources of morality and order. On the one hand, natural phenomena can affect the ruling orders of humans; on the other hand, what humans (especially the ruling class) did would also affect changes in the natural phenomena. Therefore, the ancient Chinese regard "Heaven," "Earth" and "Men" as the "three talents" of nature, they can be regarded as an interactional and unified whole. For the ancient Chinese view on nature, see Wang (2007Wang ( , 2019, also see Jiang (2021). 5 For example, TAO Yuanming陶淵明 (c. 365-427) is one of the famous recluse poets in Chinese history; his poems express a celebration of rural lives, and express his boredom with political affairs. In one of his poems, he wrote, "Long being kept in a sophisticated cage, now [I am] feeling released upon return to nature" 久在樊籠裏, 復得返自然. 6 It may also be in this sense that the answer of "Needham's Grand Question" would be as follows: Because of the main difference in the nature views between China and the West, nature has never been the object of science and technology in ancient China, and the relation between humans and nature is connected by a common emotion, rather than a one-dimensional exploration of nature. Therefore, due to the perception that nature and humans are in oneness, the logical consequences of the "discovery of nature" did not exist in ancient China. This explains why China did not take the historical lead in the emergence of modern science. For a history of technological development in ancient China and its harmonious relation with nature, see Wang and Zhu (2012, pp. 357-77). 7 For instance, in The Structure of Behavior, in one of the important early works of Merleau-Ponty, he claims that "by nature we understand here a multiplicity of events external to each other and bound together by relations of causality" (Merleau-Ponty 1983, p. 3). Obviously, we can deduce that Merleau-Ponty's understanding of nature in his early works (at least in The Sturcture of Behavior) is still a modern understanding without any perceptional and primordial depth. 8 Here, Merleau-Ponty uses the term "element" to describe the universal factor which constitutes humans, nonhumans and the world, thereby representing the influences of Greek natural philosophy on Merleau-Ponty's later thoughts. In Nature: Courses Notes from the College de France, Merleau-Ponty mentions the influence of Stoic natural philosophy on his thinking: "The Stoic meaning of the word 'nature' . . . is the idea of a sympathy, . . . the idea of Destiny, . . . this course is not a study of these elements, because in order to reintroduce them, it is necessary to transform them" (Merleau-Ponty 2003, p. 7).