Gu Kaizhi believed that form and spirit are interdependent. “Shen” is the spirit of object. Spirit is intrinsic to the object, while form is the external thing, the foundation upon which spirit exists. “For the sake of Shen, there is no departure from form [5] ”, “Shen” must be expressed through the precise molding of the form, and the precision of the form is precisely for the purpose of expressing Shen. In Gu Kaizhi’s painting theory, there are a large number of expressions about form and spirit. “The appearance is in the heart, and the hand is called its vision.” [6] When drawing a character, one should pay attention to the consistency of the external appearance and the inner emotion, and only through the artist’s hands appearing on the visible image can the spirit be conveyed. At the same time, changes in form also cause changes in spirit [4] . Gu Kaizhi believes that “if the length, rigidity and flexibility, depth, width and narrowness, and eye-dotting joints, up and down, size, thickness, there is a small loss, then the spirit and all change with it.” [6] He paid great attention to the use of the brush to show the object of spirit, the brush is the expression of the form of tools, and brush strokes are part of the form, but he does not brush strokes smoothly as the pursuit of painting, but focus on the accuracy of the contours [4] . In general, form and spirit are interdependent and inseparable.

The spirit in painting with form refers to the spirit of the object, and cannot be separated from the object to talk about writing the spirit. And as a subjective person, to recognize the spirit of the objective object, rely on feeling and cognition [4] . How to experience the objective object of the spirit, Gu Kaizhi gave the answer “to think and get”.

The so-called “Moving Thinking and Wonderful Getting”, from the literal understanding of the author’s thoughts “move” to the conception of the art object, in-depth understanding of the objective world and “wonderful get” [7] . In the object of the “mystery”, master the object of thought and feeling and characteristics, the painter and then refined and processed to artistic techniques will be the object on the picture, and ultimately become an artistic image [7] .

At the same time, some scholars believe that the “thought” in “Moving Thinking and Wonderful Getting” is neither the thought of the objective object, nor the thought of the painter, nor a combination of the two thoughts, but a kind of “understanding” [8] . This understanding is not a simple “transfer” of the painter’s thoughts and feelings, but a more complex and profound mode of thinking. It is recorded in “The New Sayings of the World” that Gu Kaizhi painted a portrait of Pei Shuzhe, and through careful observation, he found that Pei Shuzhe had hairs on his face, so he added three tiny hairs to the finished painting. This is how the artist arranges and organizes the picture through understanding and observation, using rational “understanding”.

“Choosing images to express the spirit” means conveying the spirit of a person or an object in a painting. The “Shen” is conveyed by the character image, and the value of the character image is determined by the “Shen”. “Choosing images to express the spirit” is extended on the basis of “Express Shen in Form” and “Moving Thinking and Wonderful Getting”. It is through the selection of the character image, coupled with careful painting, and ultimately achieve the effect.

Tang dynasty Zhang Yanyuan very respected Gu Kaizhi, listed Gu Kaizhi and others as “on the top grade”, and said, “Gu transport thought subtle, lapel spirit unpredictable, although the trace of the ink, its spirit floating above the sky…” At this time, Zhang Yanyuan’s evaluation of Gu Kaizhi still remained at the level of “Shen. Miao. Neng”, but it was not limited to this, and he believed that Gu Kaizhi’s paintings and character had already exceeded the scope of the evaluation system, i.e., “There is nothing more wonderful than… the divine and the marvelous… can’t be sought between the grades!” [1]

Ni Zan emphasized the “self-entertainment” function of painting. From Ni Zan’s statement in the “Self-Painted Ink Bamboo”, we can see that the main function of his paintings is to express the “Yi” to please himself [9] . The aesthetic sense of classical Chinese painting comes from the philosophical ideas of Confucianism and Taoism: Confucianism advocates entering the world, being active and enterprising, and emphasizes the educational function of painting, with regulating the social order and saving the general public as the highest goal of art; Taoism pursues avoidance of the world, indulging in the beauty of nature, and pleasing the self as the goal of painting, which is opposed to the educational function of Confucianism [10] . For Ni Zan, painting was a form of emotional support. This is also closely related to the context of the era in which Ni Zan lived. During the Yuan Dynasty, the Mongol rulers pursued a policy of ethnic discrimination, dividing all ethnic groups into four classes, with the Han Chinese at the bottom of the hierarchy, hence the phenomenon of cultural ostracism and boycott. As a result, the southern literati were forced to move from Confucianism’s “entering the world” to Taoism’s “leaving the world,” and to devote their energies to the creation of poetry and painting for their own amusement. Ni Zan’s “Yi” combines the Confucian concept of entering the world, the Taoist concept of inaction, and the Buddhist concept of transcendence, which is based on the simplicity of the Great Dao. [9]

Ni Zan’s concept of “people-oriented” painting returned to the sense of self-subjectivity. He emphasized human ethics in dealing with natural landscapes, combining his own rationality with the sensibility of painting. Taking human ethics as the subject of painting emphasizes the painter’s sense of self-expression, transforming painting from objective realism to subjective expression. He demanded that painters unify their personal character, disposition, scrolls, and brushwork, believing that reading and personal cultivation were necessary conditions for painters to paint [9] .

The essence of Ni Zan’s “Yi” is to emphasize the painter’s personal disposition, breaking through the traditional realistic concept of pursuing both the form and spirit of objects since the Tang Dynasty, and focusing more on the subjective consciousness and self-awareness of human beings [9] . This change reflects the completion of traditional Chinese painting from the importance of “Shen” to the important transition of “Yi”. Since then, literati painting began to focus on the painter’s subjectivity and individuality, advocating the venting of inner emotions through painting, with the nature of self-indulgence.