Wu became an anarchist during his stay in France in the first decade of the 20th century, along with Li Shizeng, Zhang Renjie, and Cai Yuanpei.

In 1903 in the Subao newspaper, Wu criticized the Qing government and derided then ruling Empress Dowager Cixi as a "withered old hag" and a "whore.

Although Wu was their elder by more than a decade, the three young scholars, although well-versed in the Confucian philosophy which dominated Chinese thought, were impressed by the doctrines of anarchism which flourished in France.

He later founded influential revolutionary organizations like the Society to Advance Morality and supervised radical journals like New Era and Labor, China's first syndicalist magazine.

Wu felt that the new Republic must not be menaced by the social decadence of the late Qing, evils which ranged from mah-jong and stag parties to taking second wives.

[5][6] While declining to hold office, Wu did accept Cai Yuanpei's offer join the commission on language reform, beginning work on a phonetic system for writing which would replace regional dialects.

[8] In the 1920s, along with Li Shizeng, Zhan Renjie, and Cai Yuanpei, was one of the so-called "Four Elders" of the GMD and led the anti-communist campaign which drove leftists and communists from the party and supported Chiang Kai-shek.