Knowing was an important idea in the ancient Chinese theory on knowledge, meaning knowledge and understanding. Could human acquire knowledge? Could human understand the world? On the issues, there were different opinions.
Knowing (Zhi) appeared very early in Chinese history. In Zuo Zhuan, the word Knowing was widely used. In the late Spring and Autumn Period, the understanding of Knowing was basically formed. Confucius firstly discussed the ides Knowing in a profound way. For instance, Confucius warned his disciples: "If you know, recognize that you know; if you don't know, then realize that you don't know. This is knowledge." (The Analects, Wei Zheng) Here, Confucius clearly differentiated "Knowing" from "Not Knowing." Confucius also told how he made progress in learning: "When I'm 15, I determined to learn; in my thirties, I'm independent; in my forties, I'm free of temptation; in my fifties, I know the fate; in my sixties, I'm satisfied with everything; in my seventies, I do whatever I want to do." (The Analects, Wei Zheng) Obviously, Confucius took a positive attitude towards knowledge. Afterward, many schools of thoughts in Pre-Qin Time expressed their views on knowledge and confirmed the ides Knowing, or human's ability in knowledge:
Mohism said, "Knowing means human's ability in knowledge." (The Book of Mozi, Canon I)
Xun Zi said, "What makes human to pursue knowledge is their nature and what can be understood is the law in things." (Xun Zi, Removing Obstructions)
Han Fei said, "Ear and Eye are what one is born with; action and consideration are what one does after birth." (Han Fei Zi, Explaining Lao Tzu)
Obviously, their views indicated strong color of Gnosticism.
Taoist's view on knowledge was unique. Lao Tzu expressed his deep understanding of knowledge: "One will succeed if he acts after he knows the rule; one will meet obstacle if he acts before he knows the rule." (Lao Tzu, Chapter 16) Lao Tzu clearly stated the importance of knowing the rule. Different from Confucius, Lao Tzu stressed that "One cannot bear in mind authority and subjectivity' and that "One can secure himself when he does not obtain knowledge." (Chapter 19) Certainly, Lao Tzu's view was based on the need to rule the country rather than the epistemologist stance. Chuang Tzu largely inherited Lao Tzu's view. Chuang Tzu noted that human's knowledge did not cover all in the universe. He said that "People in the past knows limited." and "One who knows that there are some he does not know has reached the highest level." (Chuang Tzu, On the Similarity between Things) Chuang Tzu's view sounded reasonable. However, Chuang Tzu fell into the trap of agnosticism:
Let me ask you. How do you know what I say I know means I do not know? How do you know what I say I do not know means I know?' (On the Similarity between Things)
One did not realize the dream when he was dreaming, or deciphered another dream in the present dream. He realized the dream only after he woke up. The great realization comes after a great dream. The stupid knows he made a dream, but he is still in the dream. (On the Similarity between Things)
And draw the conclusion that: "Human's life is limited while knowledge is unlimited. One will exhaust himself if he pursues knowledge with his limited life." (On Health)
In addition, knowledge or understanding related to the test of knowledge or understanding, which ancient Chinese philosophers had realized. For instance, Xun Zi said, "One view can be argued and tested." (Xun Zi, On the Evil of Human Nature) Han Fei said, "To justify one's view, we should see whether it accords with reality; to justify one's words, we should test it with practice." (Han Fei Zi, Killing the Treacherous Court Official) Wang Chong said, "One cannot convince other if he lists facts without evidence, no matter how persuasive his views sound." (Critical Essays, On Knowledge and Practice) Their thoughts all embodied the test of knowledge and the consistency between knowledge and fact.