In this article, I explain the importance of actuality in Wang Yang-ming’s thought, through dealing with the interrelationship between his achievements (shi-gong) and philosophy of Mind (hsin-hsüeh). In the chapterⅠ, I describe the process of Yang-ming’s banishment from Beijing to Guizhou, because his argument with the government. Because Yang-ming’s interpersonal relationship, he had no choice to write a memorial to the throne. Then he was punished for the action, and has a question of what is right and wrong in the morally degenerate society. In Longchang, Yang-ming realized that a person of noble character and integrity (jun zi) did not have any private desire. Yang-ming considered that if a person could drive out private desire herself, he was a person of noble character and integrity (jun zi). Yang-ming realized that the key point was the practical direction from the heart oneself. Hence, Yang-ming had a system of practice named the study of being a person of noble character and integrity ( jun-zi-chih-hsüeh). In the chapter Ⅱ, I explain the cause and effect of the slogan “sagehood is philosophy of Mind (sheng-jen-chih-hsüeh-shi-hsin-hsüeh ). When Yang-ming returned from Guizhou to Beijing, due to his own experience of political persecution, he was pained by the realization that social standards of right and wrong were turned upside down at that time. The causes for such condition, he suggested, had to do with people's selfishness. Selfishness subsequently led to various social and national problems. Investigating and reflecting upon Ch’eng-Chu’s philosophy, Yang-ming redefined the concept of sagehood (sheng-jen-chih-hsüeh). He proposed that the philosophy of Mind (hsin-hsüeh) as a way to attain sagehood in order to regain the political harmony of Three Dynasties (san-dai-chih-zhi). Yang-ming endeavored to promote the study of sagehood whenever he worked in Beijing or Nanking. Since he emphasizes the contents and importance of Mind in his thought, his viewpoints easily fell into the disputes of different approaches between Chu Hsi and Lu Chiu-yüan (Chu-Lu yi-t’ung). This was not Yang-ming’s intention. In order to clarify his ideas, he wrote a book entitled Chu-tzu-wan-nian-ding-lun (The final evaluation on Chu Hsi’s old age). In this book Yang-ming made two arguments. First, he illuminated that the philosophy of Lu Chiu-yüan is not Buddhist Zen. Second, Chu Hsi also paid attention to the philosophy of Mind. After the publication of this book, Yang-ming’s ideas had widespread impacts to the extent that scholars began to rethink the Ch’eng-Chu philosophy. In the chapter Ⅲ, I interpret the emergence of the concept of intuitive ability to know right or wrong (liang-zhi) through the relation between hostilities and thought. In the war of South Kan-chou, Yang-ming slowly realized that understanding of everyone’s hart (ben-hsin-chih-ming) could grasp the private desire herself. Yang-ming believed that everyone could drive out the private desire by the understanding of everyone’s hart. After Yang-Ming penetrated the difficulty of two persons (zhong-tai-chih-bian), he recognized that the understanding of everyone’s hart is the concept of intuitive ability to know right or wrong (liang-zhi). In the other hand, Yang-Ming used the practical methods of Zhou Dunyi (1017-73) and Cheng Hao (1032-85) to bear witness to his idea in the practice.