This passage comes from The Analects, Book Seven, "Shu Er": "The Master said, 'When three men walk together, there is certainly one who can be my teacher. I select their good qualities and follow them, and their bad qualities I reflect upon and correct myself.'" The meaning is: when three people walk together, among them there is surely one from whom I can learn; I can emulate others' strengths and take their weaknesses as a warning to correct myself. Confucius believed that to establish oneself in society and achieve success, one must strive for comprehensive learning. Learning should begin with the Classic of Poetry (Shijing) and the Book of Documents (Shangshu), for "without studying the Poetry, one cannot speak properly" (The Analects, Book Sixteen, "Ji Shi"). Secondly, one must also learn the state's laws and codes, for "without studying Li (Propriety), one cannot establish oneself" (same passage). This knowledge, gained through texts and documents, forms the foundation for social interaction and conduct, and is essential for becoming a member of society. Confucius began studying such knowledge early in life, stating, "At fifteen, I set my mind on learning" (The Analects, Book One, "Xue Er"). He diligently studied and extensively collated and organized texts such as the Poetry, the Documents, the Rites, and the Music. However, Confucius believed the scope of learning was very broad, encompassing not only textual study and bookish theory but also continuous improvement of personal moral cultivation and social abilities. "Teaching and learning," "cultivating virtue," and "correcting what is not good" were the learning goals he constantly reminded himself of (see The Analects, Book Seven, "Shu Er"). He maintained an attitude of humility, caution, and willingness to learn from those beneath him. He once praised Zang Wenzhong (a noble of Lu) for being "quick-witted and fond of learning, and not ashamed to ask his inferiors" (The Analects, Book Five, "Gongye Chang"); in fact, Confucius himself embodied this very quality.
Throughout his lifelong learning process, Confucius placed special emphasis on cultivating his own moral character. To this end, with a highly practical attitude, he learned from anyone and anything worthy of his study. Confucius said: "There may be those who act without knowledge, but I am not one of them. I listen widely, select what is good and follow it; I observe broadly and remember it." (The Analects, Book Seven: Shuer) There are people who pretend to know what they do not know; Confucius considered himself not such a person. He "knew what he knew and acknowledged what he did not know," never missing any opportunity to learn, listening and observing widely, choosing the good and following it. "When walking with three people, there must be a teacher for me" is a vivid illustration of this learning attitude. This comprehensive, ever-ready learning attitude permeated his entire life; he often "saw the worthy and thought to equal them; saw the unworthy and reflected inwardly on himself" (The Analects, Book Four: Li Ren). For Confucius, there was no fixed school and no specialized teacher; society itself was a great school, and all people were his teachers. Wei's official Gongsun Chao once asked Confucius's disciple Zi Gong (a gifted diplomat and merchant) where the Master's learning came from. Zi Gong replied: "Where did our Master not learn? And why must he have a constant teacher?" (The Analects, Book Nineteen: Zizhang) The Master learned everywhere, from wherever was worthy of learning—so why must he have a specialized teacher? This is the principle of "learning without a constant teacher." Indeed, as Zi Gong said, Confucius once inquired about offices from Tanzi (a ruler of the small state of Tan), asked about ritual propriety from Lao Dan (Laozi, the founder of Daoism), studied music from Chang Hong (a Zhou dynasty music master), and learned the qin (a Chinese zither) from Shi Xiang (a renowned music teacher).
Throughout his life, Confucius "learned tirelessly and taught without weariness." He was skilled both at acquiring knowledge from others and at transmitting it to them. It was precisely through this spirit of eager learning and regarding the capable as teachers, and through this attitude of learning at any time, in any place, and in all aspects, that Confucius ultimately became a great scholar and great thinker of ancient China, serving as a model of self-taught achievement for all ages.