Chen Liang 陳亮 (1143-1194), courtesy name Tongfu 同甫 or 同父, style Longchuan Xiansheng 龍川先生, was a philosopher of the Southern Song period 南宋 (1127-1279). He did not belong to the mainstream Neo-Confucian circle around Zhu Xi 朱熹 (1130-1200), but stressed a more practical application of philosophical thoughts.
Chen hailed from Yongkang 永康 in the prefecture of Wuzhou 婺州 (today's Yongkang, Zhejiang). His teachings are therefore known as the Yongkang School of Thought (Yongkang xuepai 永康學派).
From his early years, Chen was interested in politics and advocated to fight against the Jurchen Jin dynasty 金 (1115-1234) which occupied north China, and to carry out structural reforms. Chen submitted to the throne five essays (Zhongxing wu lun 中興五論) on political affairs. He obtained the jinshi degree as late as 1193 and was thereupon appointed administrative assistant to the military commissioner (jiedu panguan 節度判官) of the military prefecture of Jiankang 建康軍, but never took over the post.
In the field of philosophy, Chen cannot be clearly attributed to a certain scholarly heritage (shicheng 師承), even if he generally accepted the basic propositions of Neo-Confucianism. Yet Chen Liang observed that the famous philosophers of the time only talked of the human character (xing 性, xingming 性命) as bestowed by Heaven, without considering the relation of their theories to real life. For his critique, he was several times thrown into jail.
While Chen adopted the traditional view that everything in the world consisted of substance, he added the important proposition that everything in daily life consisted of deeds (yin yuzhou zhe wu fei wu, ri yong zhi ying wu fei shi 盈宇宙者無非物，日用之間無非事). Substance and deeds were to be brought together in a way that the universal principle (li 理, tianli 天理, dao 道) was not just implanted into the human mind or heart (xin 心), but was also to be seen in his activities. He explained that "the Way is not expressed in substance and shape, but is routinely implemented in actions and achievements" (dao fei chu yu xingqi zhi biao, er chang xing yu shiwu zhi jian zhe ye 道非出于形氣之表，而常行于事物之間者也). If wise men were in office and capable persons entrusted with public affairs, they would benefit the state and society. Yet is persons with insight into the universal principle refrained from engagement in public matters, this was of no great help to the world (ren bu li ze tiandi bu neng du yun 人不立則天地不能獨運). If efforts yielded success, this was an expression of virtue (gong dao cheng chu, bian shi you de 功到成處，便是有德), and if action was of help, this was an expression of the universal principle (shi dao ji chu, bian shi you li 事到濟處，便是有理)
Moreover, the universal principle was best to be seen in conduct and action (xing 行), not in contemplation or studies of ancient writings. In Chen's eyes, the Neo-Confucian masters like Zhu Xi or Lu Jiuyuan 陸九淵 (1139-1193) believed that it sufficed to "rectify the mind and make sincere one's intentions" (zheng xin cheng yi 正心誠意) and to "sit there with folded hands to discuss the (innately good) properties of the human character" (ditou gongshou yi tan xingming 低頭拱手以談性命). They blinded and deceived each other and discarded the practical aspects of life. Chen opted instead for a scholar to study to become a perfect man in practice (xue zhe xue wei chengren 學者學為成人). This was possible by using moral concepts like kindheartedness (ren 仁) and righteousness (yi 義) by acting, and to combine them with benefits or profit (yi li shuang xing 義利雙行). The concept of profit (li 利) was thoroughly negative in traditional Confucianism as it was seen as selfish, and interpreted as the influence of human desires (ren yu 人欲) as a maculation of the pure and morally good universal principle.
In the field of politics, Chen stressed that a sovereign had likewise to apply both attitudes, namely the traditional Confucian way of a benevolent king and that of a realist "hegemon" (wang ba bing yong 王霸并用). Chen harshly criticized Zhu Xi's view of history and politics which ignored real circumstances and instead constantly looked backed into an idealized past. Instead, useful paradigms of the past had to be imitated just as those of recent times (gu jin bing yi 古今并宜). Every generation had to carry out reforms to adapt the administrate system to the circumstances of the time. Agriculture could not go without trade, just as the latter relied on the produce of the farmers. Both professions supplemented each other, and could not be seen as morally superior (farming) or inferior (trading), as traditional Confucians did.
In his own time, some of Chen Liang's thoughts were seen as heretic, and even in later ages, they were not adopted by mainstream thinkers, but by philosophers who were deviating from the trend, like Li Zhi 李贄 (1527-1602), Huang Zongxi 黃宗羲 (1610-1695) or Quan Zuwang 全祖望 (1705-1755). Chen was also admired by Wang Fuzhi 王夫之 (1619-1692), Yan Yuan 顏元 (1635-1704) and Dai Zhen 戴震 (1723-1777).
In his political essays Zhongxin wu lun and Zhuogulun 酌古論, Chen Liang suggested to employ worthies and appoint competent persons, and to ease laws in favour to decrees (jian fa zhong ling 簡法重令).
In the 74 surviving poems of the lyric metre style (ci 詞), Chen's philosophical thoughts are expressed as well as his recommendations in the field of policy. The "patriotism" in his poems can be compared with that of the much more famous writer Xin Qiji 辛棄疾 (1140-1207). The lexicon of Chen's poems includes local expressions, sayings and even colloquial words.
Chen's collected writings are called Longchuan wenji 龍川文集 and Longchuan ci 龍川詞, and in the modern edition (Zhonghua shuju 1974) Chen Liang ji 陳亮集.