Qu is the aspirations, emotions, and interests expressed in the work of a writer or artist. His pursuit of qu determines his unique perception and comprehension of nature and life. It also determines what theme he chooses for his work and how he gives expression to it. Qu is invisible but manifests its value and appeal through aesthetic appreciation.
Ji Kang was good at explaining profundities and writing. He had a high style and fine taste. A forthright and broad-minded man, indeed! (The Jin History)
The only thing really hard to understand in the world is qu. Qu is like the hues of hills, the taste of water, the splendor of flowers, or the beauty of a woman. Even an eloquent person can hardly find words to put it clearly. Only those with empathy know it well … Qu that comes from nature is deep and mellow; if it comes from book learning, it is often shallow. (Yuan Hongdao: Preface to Chen Zhengfu’s Inspirations of the Mind)