Chinese philosophy is one of the oldest and most influential traditional philosophies in the world. It has developed distinctive philosophical concepts by exploring the relationship between man and nature and understanding the changes in history from the past to the present. It elucidates Chinese ideas on the universe, society, and life through theoretical thinking peculiar to the nation. Chinese philosophy emerged over 3,000 years ago during the transition from the Shang Dynasty (1600–1046 BC) to the Zhou Dynasty (1046–256 BC). By the Eastern Zhou Dynasty (770–256 BC), Chinese philosophy had flourished with the contending Hundred Schools of Thought. Chinese philosophy has developed in four stages: the stage before the Qin Dynasty (221–206 BC), marked by the Contention of a Hundred Schools of Thought; the stage from the Han Dynasty (206 BC–AD 220) to the Tang Dynasty (618–907), when Confucianism, Taoism, and Buddhism competed in harmony; the stage from the Song Dynasty (960–1279) to the late Qing Dynasty (1616–1911), when neo-Confucianism combining Confucianism, Taoism, and Buddhism prevailed; and the stage between 1840 and 1949, which saw the integration of Chinese and Western philosophies.

China's Xia Dynasty was established around 2070 BC. As history unfolded from the Shang Dynasty to the Western Zhou Dynasty (1046–771 BC), China saw the birth of its philosophy. Historians referred to the philosophical thoughts during the Spring and Autumn Period (770–476 BC) and the Warring States Period (475–221 BC), a time before the establishment of China's first unified, centralized state, the Qin Dynasty, as the pre-Qin philosophy.

The struggle for survival and power had made the contending vassal states anxious for bright ideas and effective strategies, which eventually fostered the flourishing of the Hundred Schools of Thought. These pre-Qin dynasties of Xia, Shang, and Zhou had made many cultural and political achievements, especially in rites, music, and law, providing a fertile ground for philosophical diversity and dynamism. As the  Treatise on Literature  in the  Chronicles of the Han Dynasty  says, the Hundred Schools of Thought were the philosophical fruits of "what had been learned from government officials," and their theories were innovations based on "ancient wisdom of the Tao (the way)." Confucians, represented by Confucius and Mencius, first acquired their knowledge from ministers of education, who helped rulers educate their subjects and promulgate their ideas, studied ancient classics, and prized ethical codes. Taoists, represented by Laozi and Zhuangzi, originally learned from historiographers, who documented triumphs and failures of the past and investigated the patterns of historical evolution. The Yin–Yang school arose from official astrologists. Regulatory officials promulgated Legalism. Mohists absorbed the ideas of temple keepers and advanced theories such as "frugality," "universal love," "exaltation of the virtuous," "reverence for ghosts and deities," "rejection of fatalism," and "identification with the superior." The School of Names originated from protocol officials. The School of Diplomacy was naturally pioneered by state diplomats, whereas government consultants started Syncretism. Such philosophical diversity fostered a growing consciousness of common nationhood and spontaneous awareness of ethical values. The meanings of Tao and Te (virtue) became the central topic for the philosophical discourse of the time—significant progress over the previous obsession with the Mandate of Heaven. Many schools advanced their theories on the Tao of Heaven, Tao of Earth, Tao of mankind, the virtues of yin and yang, and benevolence and righteousness, among other things.

The discussion of the Tao and Te started with Taoism, the root of Chinese philosophy. As the famous historian Sima Qian once noted, "Laozi first expounded on the Tao and Te with a book of more than 5,000 characters." That book is the  Tao Te Ching , which defines the Tao in three ways: the origin of all things that even precedes the Heavenly Lord, an omnipotent nothingness that unites yin and yang in harmony, and an intangible force that produces infinite possibilities. In short, Laozi explained the Tao through a naturalistic approach and believed that it should be respected through inaction. His theory was further developed by Zhuangzi, who described the Tao as an inexhaustible nothingness "with emotion and sincerity" but "without action or form." He believed the Tao "has its roots in itself and precedes Heaven and Earth" and is a state of primordial chaos more permanent and sincere than  shu  (brief) and  hu  (sudden). In contrast, Confucians approached the Tao more positively. Confucius encouraged his followers to "aspire to the Tao, hold to virtue, rely on benevolence, and rejoice in arts." In other words, he advocated apprehending the Tao and cultivating virtue. Despite the moral degeneration of his time, Confucius continued to "answer the call of human virtue" even when "aware of insurmountable challenges." He believed that "man can enlarge the Tao, but the Tao does not enlarge man." This belief laid the humanistic cornerstone of Confucianism: unremitting self-improvement. The theory was further developed by Mencius, who noted that "benevolence is what makes Man human; when embodied in Man's conduct, it is the Tao." In his eyes, the "Tao of mankind" could be cultivated through the "sense of mind" and be united with the "Tao of Heaven." While Laozi and Zhuangzi rejected the fatalistic belief in supreme deities by respecting nature and naturalness, Confucius and Mencius stressed the value of humanity by advocating virtue and good conduct. Despite their different approaches, both Taoism and Confucianism shared some common goals with mutually complementary ideologies. Together, they laid down the fundamental framework for traditional Chinese philosophy. This framework was further enriched by other schools, which also centered their discussion on the meanings of Tao and Te. One example is Guanzi and his followers, who believed that a ruler must educate his subjects with Tao and Te to build a harmonious society.

The Tao of Heaven describes philosophical inquiry into the nature of the universe. During the Shang and Zhou dynasties, most people regarded Heaven as the supreme deity and referred to it as the "Heavenly Lord." In their view, the Heavenly Lord decided everything. Aristocrats attempted to decipher the Heavenly Lord's wishes to tell their fortunes and recorded the results on oracle bones. A divination system using hexagrams appeared in the  Book of Changes  around the end of the Shang Dynasty. Later, the  Commentary on the Book of Changes  employed the hexagram system to represent eight fundamental natural phenomena as it investigated the origin and evolution of the universe. In the Western Zhou Dynasty, the belief in the Heavenly Lord gradually gave way to a more philosophical concept: the Mandate of Heaven, the idea that the universe favors a just ruler. Ji Dan, the Duke of Zhou, argued that "the Mandate of Heaven is not fixed" and "Heaven is always kind to the virtuous," stressing the importance of human conduct and virtue. Around the time when the Zhou regime lost its old capital, some poets began to question the Mandate of Heaven and even blamed it for the loss. Bo Yangfu, an imperial historian of Zhou, believed earthquakes were caused by the loss of balance between the "forces of Heaven and Earth," i.e., the yin and yang. Mozi opposed the fatalist concept embodied in the Mandate of Heaven and replaced it with a more humanistic concept: the "intention of Heaven." Laozi rejected Heaven as the supreme force and argued that the Tao was the origin of everything, which signified the progress of Chinese philosophy. Guanzi believed that  jing  (energy) and qi (force) were the source and essence of the universe. Xunzi, in the late Warring States Period, put forward the theory of humans harnessing and utilizing the "Mandate of Heaven," which meant natural laws.

The Tao of mankind is one branch of Chinese philosophy that explores questions about life and humanity. The Duke of Zhou believed, "Only the virtuous can shoulder the Mandate of Heaven." To regulate social order and public conduct, he established a series of rites and created an "honorable" genre of music. Emphasis on humanity and virtue became especially prominent after the late Western Zhou Dynasty. Confucius regarded benevolence as the highest principle of humanity and insisted, "Don't do to others what you don't want others to do to you." He defined benevolence as "self-restraint and compliance with rites," which put the concept under an established hierarchy. This approach was rejected by Mozi, who instead advocated "universal love." Laozi differed from Confucius and Mozi by arguing that life should be  wuwei  (inexertion or inaction) and  baopu  (stick to simplicity). Mencius inherited Confucian theory and emphasized the four virtues of humanity: benevolence, righteousness, propriety, and wisdom. He believed that the "four good principles" were innate to human nature and distinguished humans from animals. This belief was opposed by Xunzi, who argued that man was evil by nature. He maintained that humanity was not the direct result of human nature but the outcome of its refinement. Therefore, he also criticized Zhuangzi for being "too obscured by Heaven to understand mankind" and emphasized the importance of the transformation of nature. Zhuangzi advocated Laozi's idea of  wuwei . He advised his followers "not to extinguish the constitution of Heaven by human doing and not to extinguish the Mandate of Heaven for human purpose" and to stay away from social chaos in pursuit of a free and unfettered mental state.

Knowledge and action is another realm of philosophical discussion that focuses on the source and purpose of knowledge and the way to acquire it. Although Confucius acknowledged that "those born with the possession of knowledge are the highest class of men," he stressed the significance of learning that could help people "get possession of knowledge." He also emphasized the importance of seeing and hearing more, attaching importance to both "learning" and "thinking." Mencius further stressed the importance of rational cognition and the value of thinking, which he believed was the role of the "sense of mind," which differed from that of the sense of seeing or hearing. Mozi advanced three criteria for verifying an opinion: past experience, public perception, and the results of its application. Based on his theory, Mohists of a later period classified knowledge into three types: knowledge learned from other sources, knowledge inferred from known facts, and knowledge acquired through personal experience. They stressed the importance of all three types and acknowledged the different roles of the different learning stages. Laozi distinguished the "pursuit of knowledge" from the "pursuit of the Tao." He believed that "those in pursuit of knowledge increase their knowledge each day" whereas "those in pursuit of the Tao reduce their action each day." He also thought unbiased perception required a mind free of emotions and desires. This idea was echoed by Guanzi, who advocated abandoning subjectivity when searching for knowledge and "way of tranquility and adaptation." Xunzi elaborated on where and how to acquire knowledge. He advocated learning with an "open, calm, and concentrated" mind and stressed the necessity of "unraveling perplexities."

Name and actuality is the doctrine of the relationship between name and fact, concept and reality. During the pre-Qin period, the discussion of this issue covered many fields, including concepts, judgment, and inference. The resulting theories blazed a trail for the science of logic in China. Laozi pointed out the relativity of names, arguing that "the name that can be named is not an eternal name" and "the Tao has no name." He thought it was impossible to clarify the Tao, the ultimate origin, by names and language. This theory was further developed by Zhuangzi, who observed that "actuality" was the basis for names. Hui Shi also examined the relativity issue in his ten paradoxes, including such observations as "the sun at noon is the sun setting." Through these paradoxes, he highlighted the relativity of the similarities and differences between things. Although Gongsun Long also discussed some paradoxes, his primary concern was the relationship between abstract concepts and actual objects (or attributes). By claiming that "a white horse is not a horse," he emphasized the difference between a specific name and a general name. By claiming "the separateness of hard and white" or "a hard stone cannot be a white stone," he highlighted the separability of the names for two connected attributes. Mozi argued that a name had no value unless it was assigned adequately to actuality. Later-period Mohists classified names into three levels: general names, categorical names, and specific names. They believed each level corresponded to a different scope of actuality. Confucius advocated for the "rectification of names," stressing that each name should conform to actuality. Xunzi further developed this theory into an elaborate set of nomenclature rules. He proposed the principles of "compliance with established common sense" and "designation to represent actuality." He stated that "things that are the same should share the same name," whereas "things that are different should have different names." Based on similarity and difference, he classified names into "general terms," "super-categorical terms," and "sub-categorical terms." He believed that there were more than three levels, however, because each category had its sub-categories. He held that the key to accurately designating a name was to find the exact sub-category. Xunzi also analyzed three types of common stratagems used by sophists: mixing relevant but different names, obscuring names with complex facts, and disguising facts with inaccurate names. His theories, in effect, summed up the debate about the relationship between names and actuality in the pre-Qin stage.

This stage, a time of evolution of Chinese philosophy, can be divided into three periods: Qin and Han dynasties; Wei, Jin, Northern and Southern Dynasties; and Sui and Tang dynasties.

The Qin and Han dynasties witnessed the gradual integration of different philosophies from the pre-Qin period. The establishment of the centralized empire of Qin not only ended the age of rival vassal states but also eliminated the political need for diverging philosophies. As political needs changed, Legalism, Taoism, and Confucianism rose to dominance in succession as the ideologicalized context of the "Great Unity." The need for centralized rule raised Legalism as the official philosophy of Qin. Then, in the early Han Dynasty, the regime adopted the hands-off approach of the Huang–Lao school, as it tried to recover from the ravages of wars and avoid the same fate as the short-lived Qin. When Emperor Wudi of the Han Dynasty ascended the throne, he solicited ideas that could perpetuate his family's dynastic rule. In a proposal submitted to Emperor Wudi, Dong Zhongshu, an accomplished philosopher, educator, and politician of the Han Dynasty, suggested Confucianism. The emperor adopted his proposal, decreeing Confucianism as the exclusive official philosophy and assigning erudite of the Five Classics. Meanwhile, the elements of other schools were absorbed and integrated into the official philosophy. Although the Huang–Lao school was a Taoist branch, it absorbed many ideas from other schools, most notably Confucianism, Mohism, Legalism, the Yin–Yang school, and the School of Names. Even Dong Zhongshu, a fervent advocate of Confucianism, also incorporated non-Confucian elements into his theories. In general, the Han Dynasty marked a period of creative development for Chinese philosophy. Academic debates of the time centered on the interaction between Heaven and mankind.

Dong Zhongshu argued that Heaven and mankind could always interact with each other. To support his theory, he advanced two key propositions. The first was that "the kingly way connects Heaven, Earth, and mankind." It dismissed the pre-Qin belief that had denied such connection and established the ideological supremacy of the monarchy. The second proposition was that "Heaven and mankind are of the same kind." In his view, a monarch was charged by Heaven to ensure good governance on Earth; if he failed at his duty, he would be warned through natural calamities and obliged to correct his errors. It was an idealized attempt to find the subtle balance between the absolute power of a monarch and some necessary checks on his actions. In the Eastern Han Dynasty (25–220), this theory was echoed by a group of philosophers who combined Confucian classics with divination and superstition. Their most notable text on this subject was the  Baihu Tongde Lun  ( Comprehensive Discussions in the White Tiger Hall ). Yet, when this hybrid tradition grew popular, Wang Chong, a philosopher in the Eastern Han Dynasty, dismissed the theory as unverifiable superstitions. Instead, he reasserted the naturalistic approach of the Huang–Lao school.

Many Chinese philosophers have engaged in discussion about how the universe came into being.  The Pheasant Cap Master , a pre-Qin philosophical classic, argues that Heaven and Earth were born out of  yuanqi  (prime force in chaos without clear separation). Most philosophers of the Han Dynasty shared this view. For example, the "Heavenly Patterns" chapter in the  Huainanzi  (or  Writings of Prince Huainan ) says that "a great void gave birth to the universe, which gave birth to qi." Dong Zhongshu, in the chapter "Kingly Way" of his book  Luxuriant Dew of the Spring and Autumn Annals , believed that  yuanqi  was the entirety of qi between Heaven and Earth, and its harmony was an indicator of the "kingly way." Wang Chong also thought  yuanqi  was the innate, fundamental element of everything. In the late Han Dynasty, He Xiu concluded that "the prime thing was qi; it started with an intangible form and separated into tangible things." It evidenced the importance of  yuanqi  in the Han Dynasty's cosmogenesis. Jing Fang, who studied the  Book of Changes  from a numerological perspective, proposed a different idea. He applied his numerological theory to investigate the origin of the universe and developed a complicated cosmology.

Chinese philosophical discussion has often centered on the relationship between the human body and the soul. One influential thinker, Huan Tan, believed that a body was to a soul as a candle to its flame. Wang Chong argued that "life is sustained by energy," that "death drains the body's blood and in turn extinguishes its energy," and that "the dead will not turn into ghosts."

During the Western and Eastern Han dynasties, many philosophers investigated the underlying laws of historical evolution. Dong Zhongshu believed that history was driven by the Tao, which remained constant. For him, "the Tao is innate to Heaven; since Heaven is constant, the Tao is constant as well." Thus, he argued that dynastic changes should only be in appearance—in the form of alternating colors (black, white, and red). Sima Qian maintained that the Tao could not dictate historical evolution and emphasized the role of individuals instead. By examining the successes and failures of prominent figures, he strove to find the causes of the rise and fall of each dynasty. The  Huainanzi  noted that historical development always corresponded to the circumstances of the time. Yang Xiong affirmed the significance of inheritance and change to history. Wang Chong believed that "the present is better than the past" and investigated the economic roots of dynastic replacement. In the late Han Dynasty, Zhong Changtong dismissed the sacred authority of the monarchy and stated that no dynasty could escape the rising and falling cycle, which he called the "great law" of historical evolution.

The philosophical investigation of human nature has provided theoretical foundations for the study of ethics. Such investigation predated the Qin Dynasty. Confucius once noted that "by nature, men are nearly alike; by practice, they differ widely." Mencius believed that human nature was inherently good, whereas Xunzi thought it was evil. Gaozi (Gao Buhai) took the middle ground, arguing that it was neither good nor evil. In the Han Dynasty, many philosophers believed that human nature differed among individuals. Thus, they often classified people into different grades based on their nature. They thought that the highest and the lowest grades were hardly changeable, so they stressed educating those in between. Dong Zhongshu believed that human nature and desire were both bestowed by Heaven. In his opinion, human beings tended to be good in nature and evil in desire. Based on this belief, he classified people into three categories: the "sagacious," whose good nature outweighed their desires; the "vicious," whose desires overpowered their nature; and the "medium," whose nature and desire were roughly equal. To improve humanity, especially for those of the "medium" grade, he advocated education as a way to "solidify nature" and regulation as a way to "check desire." Yang Xiong thought "human nature is a mixture of goodness and evilness," so he suggested cultivating it with "benevolence, righteousness, propriety, wisdom, and fidelity." Wang Chong believed that human nature was born out of  yuanqi , stating, "Since  yuanqi  differs in density, human nature also varies in quality."

An age of division with frequent dynastic changes and rampant wars, the period between the Wei Kingdom (220–265) and the Southern Dynasties (420–589) witnessed the rise and decline of metaphysics ( xuanxue ). Under the threat of deadly chaos and disorder, individual consciousness awakened, sparking philosophical vitality and innovation. Buddhism and Taoism flourished.  Xuanxue , once a marginalized subject, also became mainstream, with its focus on the study of the arcane. He Yan pioneered the rise of  xuanxue  by annotating the  Analects of Confucius  with Taoist ideas. Wang Bi also took a creative approach to annotate the  Laozi  and the  Book of Changes ; unlike philosophers of the Han Dynasty, who interpreted these books with images and numbers, Wang advocated "acquiring meanings and forgetting images." This approach was echoed by Xiang Xiu and Guo Xiang, who both annotated the  Zhuangzi  in their efforts to bring out the "carefree spirit" and delve into the "arcane realm." Xiang Xiu was one of the Seven Sages of the Bamboo Grove, known for their rebellious stance against Confucian ethical code. By lifting the suffocating constraints of Confucianism, they encouraged new philosophical development. The rise of  xuanxue  marked a reversion to the dominance of orthodox Confucianism in the Han Dynasty. But the preoccupation with the study of the arcane somehow sidelined the pursuit of broad knowledge. After the Jin Dynasty (265–420),  xuanxue  gradually declined and blended with Buddhism, which steadily gained popularity and became the de facto state religion of the Southern Dynasties. Meanwhile, religious Taoism also established its theoretical system.

Ontological discourse about the essence of the universe focused on the states of being and nonbeing. He Yan and Wang Bi both believed that "nonbeing is the fundamental essence of the universe." For them, nonbeing was "beyond name and form," "absolute and capable of accomplishing anything," and "the basis for the existence of being." Conversely, Pei Wei argued in his essay that all things were born out of being, which was self-born. His claim was supported by Guo Xiang, who stressed the spontaneous "self-production" and "self-transformation" of things. In his view, "things come to be what they are," so no one could question the reason for or cause of being.

Philosophical arguments arose about the relationship between the Confucian ethical code and the Taoist respect for nature. Wang Bi discussed the issue from the perspective of nonbeing and being. In his view, nature was the basis for such code, just like nonbeing was the basis for the existence of being. Thus, he did not think the two contradict each other but insisted that the Confucian ethical code follow nature's way. Xiang Xiu also tried to reconcile such code and nature, arguing that "Confucianism and Taoism are a common thread." Guo Xiang went further to claim that to follow such code was to observe nature. In his view, the very existence of things was natural, and the social hierarchy and ethical codes were "in conformity with nature and Heaven." He also argued that sages were "outwardly engaged with mundane affairs but internally occupied with deep reflection." In other words, they followed code in their worldly duties but followed nature in their minds. Thus, he believed there was no need to separate the two as opposites. Other scholars such as Ji Kang and Ruan Ji saw the contradiction as irreconcilable. They thought that the Confucian ethical code was a hindrance to humanity and should be discarded in favor of nature.

This philosophical argument is about the relationships between language, thought, information, and truth. The  Book of Changes  says, "writing cannot fully encompass language, and language cannot fully encompass meaning…so the Sage created the images (hexagrams)." Based on the book, Wang Bi further argued that the real essence was meanings, not words or images. In his view, "words are interpretations for images" and "images are carriers of meanings." Thus he advocated "understanding images and forgetting words" and "acquiring meanings and forgetting images." Yet, he overlooked another vital role of words and images: they could help reinforce the understanding of their underlying meanings. In contrast, Ouyang Jian argued that language was sufficient to express all thoughts and concepts. For him, names could change to match the things named, and words could change to match the principles worded—just like an echo responding to its source sound.

Philosophers have debated whether the soul could survive without the body. Buddhism emphasizes karma during the reincarnation of a person. It was a process by which his soul is transmigrated into another body after death. Fan Zhen dismissed this belief system in his famous treatise  On the Destructibility of the Soul . In his view, the body was the substance of the soul, whereas the soul was a function of the body; and no function (soul) could exist without the substance (body). Taoists viewed the issue from a different perspective. Ge Hong believed that "the body needs the soul to thrive" and advocated physical and spiritual cultivation for prolonged life, ideally to the point of immortality. This belief was shared by many Taoists of the time, such as Kou Qianzhi and Tao Hongjing, who both became devoted alchemists in search of the elixir of immortality.

In the Sui and Tang dynasties, Confucianism, Taoism, and Buddhism were all influential in their own ways. They competed in harmony and, to some extent, blended with one another. This trend reached its peak during the High Tang period, an age featuring a prosperous economy and an open society. Confucianism not only maintained its role as an ethical guide in government regulations, imperial examinations, and family affairs but also received a boost in literature thanks to the Classical Prose Movement led by Han Yu and Liu Zongyuan. However, its development was limited due to a lack of philosophical innovation. Taoism won the favor of the Tang imperial family, who shared the same family name Li with Laozi, whose name was Li Er. Nevertheless, the religious theories of Taoism were still in their infancy and could not match the profoundness of Buddhism. Some of its ideological concepts and logical paradigms were even borrowed from Buddhism. Therefore, it was Buddhism that led the philosophical innovation of the time, as it evolved into several schools with distinctive Chinese theories, most notably the theories about the Buddha-nature. Meanwhile, advocates of the three philosophies debated the origins of human nature and desire. This debate not only dominated the philosophical scene of the time but also enriched the fundamental theories of Chinese Buddhism.

Philosophical and religious discussion about Buddha-nature focused on the conditions and requirements for mortals' attainment of Buddhahood. When it entered its golden age during the Sui and Tang dynasties, Buddhism evolved into several schools in China, including Weishi, Chan, Huayan, and Tiantai. Weishi (or Consciousness-Only), a branch based on the Yogacara school of Indian Buddhism, stressed that the attainment of Buddhahood required the enlightenment of consciousness. The Chan, Huayan, and Tiantai schools of Chinese Buddhism agreed on universal Buddha-nature principles but differed in details of the conditions and requirements for attaining Buddhahood. The Chan school, the most distinct Chinese branch, stressed the innerness of Buddha-nature. One of its patriarchs, Huineng, thought meditation was unnecessary because the human mind was born pure. Instead, he advocated "practicing virtues and refraining from evils," which echoed traditional Chinese philosophy. The Huayan school emphasized the innateness of Buddha-nature, arguing that it was the inborn nature of all beings. Huayan adherents advocated meditation to empty the mind of desires and anxieties to attain Buddhahood. The Tiantai school stressed the inclusiveness of Buddha-nature, believing that it existed in all kinds of dharma. After the mid-Tang Dynasty, Zhanran explicitly included non-sentient things when promoting the Tiantai theory. In his view, even bricks and stones had Buddha-nature. In the quest to attain Buddhahood, the school was even more attentive to meditation than Huayan.

A relevant philosophical inquiry was the Confucian investigation of human nature and emotions. Kong Yingda employed metaphors to explain the relationship between the two, stating that human nature (like water) was the substance of emotions (ripples), and emotions were the phenomena of human nature. Han Yu defined human nature as ethical virtues (such as benevolence, righteousness, propriety, wisdom, and fidelity) and defined emotions as mental states (pleasure, anger, sorrow, joy, love, hatred, and desire). He also divided people into three grades: good, evil, and medium, whom he thought "could be guided up or down." Li Ao later developed this theory, arguing that "human nature is good and desires are evil." The theories of Han and Li laid the intellectual groundwork for the neo-Confucianist debate on heavenly principles and human desires in the Song and Ming dynasties.

Liu Zongyuan and Liu Yuxi both reinvestigated the relationship between Heaven and mankind. Liu Zongyuan argued that Heaven was not sentient and could not "reward accomplishments or punish wrongdoings." He also believed that "before Heaven and Earth came into being, the only thing that existed was  yuanqi ." Liu Yuxi thought mankind could sometimes triumph over Heaven, so he advocated ethical and legal codes as the way to reward the good and punish the evil. He also criticized the belief in the interaction between Heaven and mankind, claiming that the two "do not interfere with each other." He posited that "Heaven cannot control worldly governance, and mankind cannot change seasons."

Traditional Chinese philosophy reached its zenith in the Song and Ming dynasties. The Song Dynasty reunited China after more than two centuries of chaos and upheaval, which had left the nation in social disorder and moral depravity. It plunged the people into disillusion and confusion. Facing this grave crisis, a new generation of Chinese philosophers began to rebuild ethical norms and national ethos. Neo-Confucians made the most notable breakthrough in the Song and Ming dynasties. They incorporated Taoist and Buddhist ideologies into classic Confucianism and established an encompassing theoretical system. Their pioneer was Cheng Yi, who advanced the  tianli  (heavenly principle) concept from his personal insight. From then on, it became the fundamental concept for a new age of philosophy, which saw neo-Confucianism's rise to dominance. The school centered its investigation on  li  (principle), qi (force),  xin  (mind), and  xing  (nature). It marked a significant turn from tradition and changed many previous perceptions. The Tao became a metaphysical ultimate, Heaven and mankind became unified, the arcane realm turned clear and open, and the mind became the bond uniting human nature and emotions. Many sub-schools flourished, most notably Lian, Luo, Guan, Su, Xin, Shu, Min, Daonan, Xiangshan, Jinhua, Yongjia, and Yongkang. They rivaled yet enriched each other, investigating  li  from different angles and with original ideas. Together, they epitomized this golden age of Chinese philosophy: broad in scope, subtle in detail, and inclusive of the legacies from the past 2,000 years. This age was unprecedented in both the number of its schools and the level of its accomplishments.

The concepts of  li  and qi are unique to Chinese philosophy and invite inquiry into the essence of the universe. In neo-Confucianism,  li  is the principle or pattern, whereas qi is the physical existence or instrument. Zhang Zai believed all things and phenomena have their roots in qi. He criticized the Taoist belief that "being was born out of nonbeing" and argued that qi was the essence of the universe. In his view, the Tao was the dispersion and condensation of qi, whose change was governed by  li . Wang Anshi further developed the idea of qi, claiming that  yuanqi  was the substance of  chongqi  (the qi uniting the opposite forces of yin and yang). Zhou Dunyi also explored the concepts of yin and yang in his treatise,  Explanation of the Diagram of the Great Ultimate . In his view,  taiji  (Great Ultimate) produced yang in its movement and generated yin in its tranquility; the interaction between yin and yang created the Five Elements, which in turn gave birth to all things. Cheng Hao and his brother Cheng Yi built their philosophies on the concept of  li , which they believed governed all existence. They also regarded  li  as having both natural and ethical attributes. Cheng Hao claimed that "Heaven and principle are the same" and discussed the difference and unity of the "Tao" and "instrument." Cheng Yi thought that qi was a physical essence, whereas  li  was metaphysical and the ultimate substance of all things. Zhu Xi absorbed the theories developed by Zhang Zai and the Cheng brothers, agreeing that  li  was more fundamental than qi. He stated: " Li  is the metaphysical Tao and the substance of all beings, whereas qi is the physical instrument." Thus, he thought that  li  preceded all things and phenomena. When annotating the  Explanation of the Diagram of the Great Ultimate , Zhu Xi defined  taiji  as  li . These " li -first" theories were challenged by many philosophers in the Ming and Qing dynasties. Luo Qinshun argued that " li  exists in qi." In his view, qi's changes gave birth to all things and phenomena, and the pattern of these changes was  li . Wang Tingxiang regarded qi as a physical carrier for  li , and insisted that  li  could not exist without qi. Wang Fuzhi developed the "qi-first" theories into a comprehensive theoretical system. He argued that "the existence of  li  depends on qi" and "all things are physical existence." Therefore, for him, the Tao was just the pattern for things. His theories were inherited by Yan Yuan and Dai Zhen, who discussed the relationship between  li  and qi. Yan believed that  li  and qi were two inseparable sides of the Tao, whereas Dai thought  li  was the pattern for the changes of qi. Dai also argued  li  was what distinguished things from one another.

Many Chinese philosophers have pondered the relationship between the mind, human nature, and the physical world. Zhang Zai believed human beings had two kinds of nature. One was "heavenly nature," which was innate to everything in the universe; the other was "dispositional nature," which was the outcome of the mechanisms of the human body. He also claimed it was the mind that united human nature and emotions. Cheng Hao defined "heavenly nature" as  li . His brother Cheng Yi believed "human nature" was  li , which encompassed benevolence, righteousness, propriety, and wisdom; he went on to note that the tangible form of human nature was  xin  (heart/mind), which had two sides: substance and function. Zhu Xi further developed the theories of Zhang Zai and the Cheng brothers. He thought that the difference between heavenly nature and dispositional nature was precisely the difference between  li  and qi. He believed that the mind's substance was human nature, that its function was emotion, and that its cognitive capabilities came from the "unity of  li  and qi." He also stressed the difference between the mind and  li , believing the two were related but not the same. This belief was challenged by Lu Jiuyuan, who thought that the mind, human nature, and  li  were all the same. Based on this argument, he even claimed, "the universe and my mind are the same." To cultivate human virtues, he advocated "exploiting the original mind," which he believed was the mind of benevolence, righteousness, propriety, and wisdom. His theories were inherited by Wang Shouren, who argued that "there is neither principle nor matter outside the mind." Some philosophers, especially those who believed " li  exists in qi," took a monistic approach toward human nature. For them, human nature was entirely dispositional. Wang Fuzhi criticized the concept of "dispositional nature" as unnecessary, and Yan Yuan stressed that "human nature cannot exist or manifest without disposition." Dai Zhen went further to define human nature as  xueqi  (vitality and disposition) and  xinzhi  (mind and cognition), which were based on yin, yang, and the Five Elements. He also advanced an original materialistic theory:  li  existed outside the mind but could be perceived by the mind.

Some modes of philosophical inquiry probed into human knowledge and its relationship with action. Zhang Zai divided human knowledge into two types. One was "knowledge of things," which was acquired from sense perception, while the other was "knowledge of the Tao of Heaven," which was gained through "virtuous nature." He emphasized the relationship between knowledge and virtue and advocated acquiring knowledge of the Tao of Heaven with moral cultivation. Cheng Yi also discussed "knowledge gained through virtuous nature," but he gave it a more rational definition as "knowledge of principles." To acquire such knowledge, he advocated investigating things, arguing that studying the principles of things was the right way to grasp the utmost principle. He also believed that action should be taken based on knowledge. Zhu Xi further developed Cheng's theories, noting, "With respect to order, knowledge comes first; with respect to importance, action is more important." He also emphasized the investigation of things as the way to acquire knowledge. Lu Jiuyuan dismissed this method as too tedious. Lu believed that  li  was innate to the mind, so he advocated introspection for  li . Wang Shouren proposed the "unity of knowledge and action" to stress their inseparability. This opinion was criticized by Wang Fuzhi, who was more concerned with their difference. Although he advocated that the two should complement each other, he emphasized the priority of action, arguing it was the basis for knowledge.

The unity and conflict of opposites and the cause of change were essential topics for Chinese philosophers. Zhang Zai believed qi was a unity of conflicting opposites. In his view, the conflict caused the change of qi, and the unity made it unpredictable. He also thought there were two types of change: one was conspicuous, and the other was subtle. The two types could transform into each other during the evolution of things. Cheng Hao stressed that everything had an opposite. In his eyes, the existence of opposites was the root of development. Cheng Yi believed that any development would reverse itself upon reaching a certain limit. Zhu Xi further developed the theories of Zhang and the Two Chengs. He argued that everything had an opposite (such as "east and west," "up and down," "summer and winter," "day and night," and "birth and death"), but he also believed that everything contained opposites itself (such as the "front and back" and "inside and outside" of an object). He also thought that the existence of opposites was the cause of change. Wang Fuzhi stressed the connection and transformation of opposites. He believed that opposites were "fundamentally different" yet "closely connected"—not connected simply by a bond, but dynamically by their mutual penetration and transformation.

From the Song Dynasty to the late Qing Dynasty,  li  (principle), qi (force),  xin  (mind), and  xing  (nature) remained the central issues of Chinese philosophy. There were several influential schools: the School of neo-Confucianism that stressed the supremacy of  li  (led by Cheng Hao, Cheng Yi, and Zhu Xi), the School of Force that regarded qi as the fundamental essence (led by Zhang Zai, Luo Qinshun, Wang Tingxiang, Wang Fuzhi, and Dai Zhen), the School of Mind that prized the role of  xin  (led by Lu Jiuyuan, Yang Jian, Chen Xianzhang, Zhan Ruoshui, and Wang Shouren), and the School of Nature that focused on  xing  (led by Hu Hong). Another notable school was the School of Utilitarianism led by Chen Liang, Ye Shi, and Yan Yuan, who stressed the value of empirical knowledge and practical experience.

Modern Chinese philosophy developed centering on questions about the right path for the nation. This trend was pioneered by early reformist philosophers such as Gong Zizhen, Wei Yuan, and Zheng Guanying, who sought the way for national rejuvenation after the Opium War of 1840. However, these theories were still in their infancy and failed with the country's defeat in the Sino-Japanese War (1894–1895). Mature reformist philosophies—advanced by a new generation of progressives including Kang Youwei, Tan Sitong, Yan Fu, and Liang Qichao—peaked during the Hundred Days of Reform (Wuxu Reform) in 1898, marking the formation of modern Chinese philosophy. After the failure of the reform, revolutionary theories gained momentum thanks to the efforts of people like Sun Yat-sen and Zhang Taiyan, who incorporated evolutionism into their philosophies. In the 1910s, a large number of radical democrats emerged as part of the New Culture Movement. Inspired by the October Revolution under the Soviet Union and the May 4th Movement in 1919, many of them, such as Li Dazhao and Chen Duxiu, embraced Marxism. After the May 4th Movement, Chinese Marxists spread their philosophy across the country and enriched it with their revolutionary experience. Meanwhile, other modern Western philosophies were also introduced into China, including John Dewey's pragmatism, Ernst Mach's positivism, Bertrand Russell's neorealism, Henri Bergson's philosophy of life, Arthur Schopenhauer's voluntarism, and Friedrich Nietzsche's theory of the  Übermensch  (Superman). These theories were not only employed to reinvestigate traditional fields such as logic and epistemology, but also combined with traditional Chinese theories to create new philosophical systems such as vitalism, practicalism, and the "neo-schools" of neo-Confucianism and Weishi (Consciousness-Only). Proponents of these rival philosophies debated a wide range of issues, most notably socialism, problems and doctrines, science and outlook on life. Among supporters of Marxism-Leninism, there were also campaigns against dogmatism and subjectivism.

From Gong Zizhen to Zheng Guanying, most early reformist thinkers still discussed cosmology with traditional Chinese concepts such as Heaven and Earth, Tao,  taiji , and qi. Around the turn of the 20th century, a new generation of reformists embraced Western science in their philosophical inquiries. Kang Youwei re-examined the theory of qi with modern concepts of "heat and gravity," "light and electricity," and "change in essence," whereas Tan Sitong redefined qi as ether. Yan Fu went even further to state that the whole universe was the result of evolution "driven by matter and force." Sun Yat-sen consciously based his cosmology on natural science. He once wrote, "The universe began with the movement of ether, which produced electrons. Electrons combined into elements; elements merged into the matter; and matter aggregated into the Earth." Chinese Marxists developed a materialistic cosmology under the guidance of Marxism. Qu Qiubai noted that "the Marxist cosmology is based on the materialistic theories about change." In his view, all kinds of matter "are in constant change and evolution, which is subject to the dialectical laws." Li Da wrote in his  Outline of Sociology , "The world is an evolving unity of matter. Movement, time, and space are fundamental forms of the existence of matter."

Many modern Chinese philosophers investigated the underlying laws of historical evolution. Gong Zizhen and Wei Yuan acknowledged the evolution of history but still stressed the mind as the basis for all changes and improvement. Kang Youwei believed that human society would evolve through three stages: the "Age of Disorder" (autocratic monarchy), the "Age of Approaching Peace" (constitutional monarchy), and the "Age of Universal Peace" (democracy). Tan Sitong went further to denounce both autocratic monarchy and Confucian ethical code as the "rules of disorder," which should be rooted out to create an equal society. Yan Fu approached the issue from the perspective of scientific theories of evolution, whereas Liang Qichao dismissed the theory of the dynastic cycle by emphasizing the role of individual heroes. Zhang Taiyan also took an evolutionary approach, arguing that both good and evil would evolve. Thus, he believed that revolutions were necessary. Sun Yat-sen emphasized the role of people's livelihoods, insisting that the desire for survival drove historical evolution. Materialists like Li Dazhao and Cai Hesen advocated the investigation of production relations and class struggles. Based on Marxist theories and the experience of the Chinese revolution, Mao Zedong concluded that "the people are the only driving force in the making of world history" and developed Marxist historical materialism based on the Marxist mass viewpoint.

The era between 1840 and 1949 witnessed fundamental transformations of the Chinese society, which made discussions on change and development popular among the public. Before the Sino-Japanese War (1894–1895), many thinkers of different stances had already stressed the necessity of change, including reformists like Gong Zizhen, Wei Yuan, Zheng Guanying, Hong Xiuquan, Hong Rengan, and Wang Tao. Around the Hundred Days of Reform in 1898, a new generation of reformist philosophers embraced the Western science of evolution, combined it with traditional Chinese ideas about change, and advanced a set of new theories on social evolution. Revolutionaries developed their theories of social evolution by incorporating philosophies of revolution. They advocated revolution to speed up social evolution for the common good. Based on Marxist theories and the experience of the Chinese revolution, Mao Zedong developed a theoretical system of dialectical materialism with Chinese characteristics. It has provided a systematic explanation for the laws of social development. Human society, it argues, always develops from a lower stage to a higher stage in a spiral pattern, alternating between quantitative change and qualitative change.

Li Da held that cognition was the reflection of the physical world in human consciousness regarding the relationship between knowledge and practice. In his view, knowing was a dialectical process that started with action and eventually returned to action; action was the basis of knowledge, while knowledge was the motive for action; and practice could verify knowledge and (through verified knowledge) actively change the physical world. Based on the experience of the Chinese revolution, Mao Zedong wrote a series of treatises. His  On Practice  advocates an epistemology based on practice, which unites knowledge and practice with dialectical materialism. His  On New Democracy  defines Marxist epistemology as the "active, revolutionary theory of reflection." He also advanced many realistic principles such as "basing every action on reality," "seeking truth from facts," and "linking theory with practice." These ideas have played a significant role in guiding the Chinese revolution and the construction of the country.

One of the major independent philosophies in the world, Chinese philosophy differs from Western and Indian philosophies in several aspects:

1) Chinese philosophy has a long history and is well developed. Back in the 12th century BC, the  Book of Changes  already led the world in philosophy with its unique theories. During the Eastern Zhou Dynasty, a wide range of theories were developed by the Hundred Schools of Thought, which brought Chinese philosophy to a level that was rarely matched in the world at the time. After the Han Dynasty or the Middle Ages in the West, China remained a world leader in science and technology. With the continuous development of social thinking and natural sciences and the conflict and integration of native Confucianist and Taoist philosophies with foreign Buddhist philosophy, Chinese philosophy has achieved a high degree of development.

2) Traditional Chinese philosophy has been integrated with the study of Confucian classics rather than theological canons. In Europe, theology dominated the ideological arena in the Middle Ages, when philosophy was only a humble affiliate. In contrast, although religions also played an active role in Chinese society, they have never prevailed over philosophy. Instead, the two most influential religions, Taoism and Buddhism, have greatly enriched Chinese philosophy. Although Confucianism inherited some mystical concepts, such as the Mandate of Heaven, it has never encouraged belief in any anthropomorphic god from ancient classics. Instead, its followers usually focused on the investigation of human society and the promulgation of ethical codes. Unlike the once cutthroat contention of Western religions, Confucianism, Taoism, and Buddhism have remained friendly rivals to one another. With their complementary accomplishments, the three jointly brought Chinese philosophy to its zenith.

3) Traditional Chinese philosophy has also been infused with ethics. Its cosmology and epistemology overlap with morality in many aspects. In the pre-Qin period, Confucianism, Taoism, and Mohism all based their ethical principles on the "Tao of Heaven." In the Han Dynasty, Dong Zhongshu proposed his "Three Cardinal Guides" with the theory of yin and yang. In the Song and Ming dynasties, neo-Confucians advocated benevolence by arguing that all human beings shared the same qi and regarded  li  as both the essence of the universe and the principle for ethical codes. Many traditional teachings are meant for acquiring knowledge and cultivating virtue. Mencius taught his followers the "reflection on how to be sincere"; Xunzi advocated the "maintenance of an open, calm, and concentrated mind"; Zhu Xi and the Cheng brothers encouraged the "investigation of things"; and Lu Jiuyuan and Wang Shouren recommended the "exploitation of the original mind."

4) Chinese philosophers tend to think in the context of unity, integrity, and continuity. Thus, they have developed a long tradition of dialectical investigation. Despite their different terminologies, many Chinese philosophical schools have shared the same concerns about the contradiction, movement, development, and transformation of things and opinions. They have regarded the evolution of the universe as a series of creation and transformation processes and stressed the connection and unity of different things and concepts, such as Heaven and Earth, motion and motionlessness, and the body and the soul.

5) Chinese philosophers have developed a unique set of profound concepts, such as Tao (the way),  li  (principle), qi (force),  xin  (mind),  xing  (nature),  taiji  (Great Ultimate), and the complementary opposing forces of yin and yang. This tradition had already borne significant fruit before the Qin Dynasty, as the Hundred Schools of Thought advanced their concepts from different perspectives. In the Wei and Jin period, many philosophers were engaged in "analyzing names for investigating principles," bringing new development to the application of concepts. During the Song, Yuan, Ming, and Qing dynasties, the development of conceptual categories reached a new acme. Many traditional categories were given new meanings, gradually forming traditional concepts and categories unique to Chinese philosophy and producing philosophical monographs explaining concepts and the "literal meanings" of categories. Their uniqueness distinguishes Chinese philosophy from its Western and Indian counterparts.

Chinese philosophy has contributed usefully to the development of human civilization and made rather extensive influence on the philosophies of Japan, the Korean Peninsula, Vietnam, and other Southeast Asian countries as well as some Western countries.