His father, Tang Yongtong, was a scholar of Chinese traditional philosophy and President of Peking University (PKU).

[3] In 1958, Tang was affected by the Anti-Rightist Movement, when he objected to his wife being declared a "Rightist" and expelled from the Chinese Communist Party (CCP).

[3] After the start of the Cultural Revolution in 1966, he lost his teaching position at Peking University and was sent to the countryside to perform manual labour.

[2] In May 2014, CCP general secretary Xi Jinping visited Tang at Peking University, and lauded him for his "exceptional contribution" to the promotion of traditional Chinese culture.

During the 1989 Tiananmen Square protests and massacre, he joined a group of eminent scholars to plead to the government for leniency for the dissident Wei Jingsheng, who had been imprisoned for a decade for advocating democracy.