When the 1898
戊戌变法 (Hundred Days' Reform) collapsed under Empress Dowager Cixi's coup, Tan refused to flee, saying
各国变法,
无不从流血而成,
今日中国未闻有因变法而流血者,
此国之所以不昌也 ('no country has achieved reform without bloodshed; let me be the first in China'). His philosophical work 《
仁学》 (On Benevolence) fused Confucian, Buddhist, and Western ideas.