The *I Ching* (Book of Changes) is the foremost of all classics and the source of the Great Way. Its profound meaning and far-reaching implications permeate a philosophical exploration of the laws of heaven and earth and the principles of human affairs. It is said that "the *I Ching* does not speak of ghosts," not because the word "ghost" is entirely absent from its text, but because its core thought does not involve superstition or supernatural phenomena. Instead, it focuses on elucidating the principles of yin and yang, good fortune, misfortune, regret, and shame. While the word "ghost" may appear occasionally, its meaning is always categorized within the realms of human affairs, history, or cosmology, distinct from later superstitious beliefs about the netherworld. The following will analyze the true meaning of the word "ghost" according to the order of the text and elucidate the profound philosophical thought of "harmonizing good and bad fortune with ghosts and spirits" in the *Wenyan* (Commentary on the Text), thus clarifying the rational spirit of *I Ching* studies. The third line of the *Ji Ji* (Completion) hexagram states, "Gaozong attacked Guifang, and conquered it in three years." The fourth line of the *Wei Ji* (Not Yet Complete) hexagram states, "Zhen used to attack Guifang, and after three years there was a reward from a great state." Scholars have traditionally interpreted "Guifang" in these two instances as the name of an ancient state. The oracle bone inscriptions from Yin Ruins already contain records of the "Guifang," a tribe located to the west of the Shang people and actually existing during the Shang and Zhou dynasties. Gaozong, also known as Wu Ding, the ruler who revived the Shang dynasty, waged war against the Guifang, a significant historical event. The hexagram texts refer to this event to illustrate a principle through history. The *Ji Ji* hexagram signifies the completion of a task, hence the phrase "conquered in three years" to symbolize the difficulty of success, warning against rash actions and especially the need to stay away from "petty people." The *Wei Ji* hexagram signifies the incomplete task, hence the phrase "rewarded in three years" to symbolize the eventual reward for hard work. Here, "Gui" is merely a component of the name of a specific state, without any connotation of ghosts or spirits. Early scholars, such as the Song dynasty scholar Bao Yunlong in *Tian Yuan Fa Wei*, explicitly stated that interpreting the *I Ching* requires exploring the mysteries of creation; if one interprets it apart from the workings of heaven and earth, it leads to heresy. Therefore, the phrase "conquering the Guifang" is purely a historical account to demonstrate wisdom in dealing with the world, a prominent example of the *I Ching*'s principle of "using the way of heaven to illuminate human affairs." As for the ninth line of the hexagram "Kui" (睽), which reads "Kui Gu, Jian Zi Bu He Tu, Cheng Gui Yi Che," the word "ghost" often raises suspicion. However, upon closer examination of its context, this line describes a hallucination experienced by a person in a state of isolation and fear. "Seeing a pig carrying mud" is already an absurd image, and "a cart full of ghosts" is an illusion born from extreme fear. Wang Bi's commentary, "Seeing ghosts filling the cart, alas, how strange!" precisely points out that this is an illusion born of suspicion, not a real ghost. The following lines, "First the bow is drawn, then the bow is laid down; not bandits, but a wedding procession," reveal the truth: initially wary and ready to shoot, but ultimately relieved and laid down the bow and arrow, because the approaching party is not a bandit, but a wedding procession. This passage vividly illustrates the cognitive errors caused by separation and suspicion, and the process of the truth finally being revealed and doubt turning into harmony. The appearance of "ghost" here is entirely a metaphorical image of psychological illusion, its philosophical meaning lying in revealing how subjective bias obscures objective reality, and has nothing to do with superstition. Some scholars have further argued that this scene may be related to a special ancient marriage ceremony, which travelers initially found incomprehensible and frightened, hence describing it as a "ghost." This interpretation also grounds the "ghost" in the description of ancient customs, rather than promoting matters of the netherworld. Throughout the ancient texts of the *I Ching*, the word "ghost" either refers to a state or symbolizes illusion, never departing from the realm of historical and real-world experience. This aligns with the fundamental spirit of the *I Ching*: observing the heavens to discern the changes of time, observing human affairs to transform the world. Its focus is on the changing laws of the real world and the governance principles of human relations and society. However, the *Wenyan* commentary on the *I Ching*, when expounding on the realm of the "great man," does indeed contain the phrase "in harmony with Heaven and Earth in virtue, with the sun and moon in brightness, with the four seasons in order, and with the spirits in good and bad fortune." How should "ghosts and spirits" be interpreted here to avoid contradicting the philosophical essence of the *I Ching*? Great Confucian scholars from the Song Dynasty onward offered extremely subtle and rational explanations, many of which are collected in the *Complete Library of the Four Treasuries*. Their core argument is to thoroughly philosophically transform "ghosts and spirits" into the movement and function of Yin and Yang in the universe. Zhu Xi elaborated on this in particular detail. His theory generally considers "ghosts and spirits" as "the traces of creation," the inherent abilities of Yin and Yang. The so-called "ghosts" symbolize the contraction, gathering, and storage of Qi; the so-called "spirits" symbolize the expansion, development, and growth of Qi. In terms of the four seasons, the expansion of Qi in spring and summer is "spirit," while the contraction of Qi in autumn and winter is "ghost"; in terms of day and night, daytime is "spirit," and nighttime is "ghost"; in terms of life, vitality and vigor are "spirit," while aging and death are "ghost." Therefore, the *Xici Zhuan* states, "Essence and Qi become things, wandering souls become changes; thus, one understands the nature of ghosts and spirits." This does not describe a personified ghost, but rather explains that the "essence and Qi" constituting life, when aggregated, become things (life), and when dispersed, change (death). From this, one can understand the state of the gathering, dispersing, and waxing/wandering of Yin and Yang (i.e., ghosts and spirits). Zhang Zai's assertion that "ghosts and spirits are the inherent abilities of the two Qi" is a classic definition of this concept in Confucian philosophy of Qi transformation. Therefore, the true meaning of "harmonizing with ghosts and spirits in terms of good and bad fortune" refers to the actions of a "great person" who not only conforms to the manifest laws of heaven, earth, sun, moon, and four seasons, but also understands and grasps the profound and unseen mechanisms of Yin and Yang's waxing and waning, and the waxing and waning of Qi, which determine the life and death of all things and the success or failure of events. The signs of good and bad fortune are foreshadowed in the changes between the visible and invisible. The so-called "harmonizing with fortune and misfortune" means understanding and conforming to the inevitable trend of the waxing and waning of Yin and Yang. When Qi (spirit) is in its "stretching" phase, one should strive for success; when Qi is in its "bending" phase (ghost), one should retreat without blame. In this way, every action will be timely and every move will be without error. This view completely rejects the superstitious connotations of praying to the netherworld for blessings and warding off disasters, instead elevating "ghosts and spirits" to a supremely subtle objective law and driving force in the universe. Cheng Yi stated directly: "Ghosts and spirits are merely a creation." This "creation" refers to the creative and nurturing function of heaven and earth. A virtuous person, with sincere reverence, serves others as if they were serving gods; the principles are interconnected. Therefore, "knowing the way of life is knowing the way of death; knowing the way of serving others is knowing the way of serving gods." In conclusion, the three instances of the word "ghost" in the *I Ching* all have specific historical or psychological references and are by no means advocating matters of the netherworld. The "ghosts and spirits" mentioned in the *Yijing* (Book of Changes) have, through the interpretations of later Confucian scholars, especially those of the Song Dynasty, based on the classics recorded in the *Siku Quanshu* (Complete Library of the Four Treasuries), been thoroughly transformed into a philosophical category describing the movement and changes of Yin and Yang in the universe. The entire study of the *Yijing*, from its hexagram symbols to its commentaries, is dedicated to revealing the universal principle that "the alternation of Yin and Yang constitutes the Dao," aiming to "understand the will of the world, establish the affairs of the world, and resolve the doubts of the world." It teaches people to understand the ways of advancement, retreat, survival, and extinction by observing the changes in all things in heaven and earth, and to align themselves with the order of the universe by cultivating their own virtue. This is a profound philosophy of nature and morality, rooted in reason and experience, and guided by humanism and education. Hence the saying "The *Yijing* does not speak of ghosts," the profound meaning of which lies in this: it transcends the fear and supplication for supernatural forces, directly pointing to the inherent laws of the universe and human life, thus establishing an important early rationalist tradition in Chinese culture.