[1] Huan was a close associate of the court astronomer and mathematician Liu Xin, as well as the author and poet Yang Xiong.
In addition to his many rhapsodies, essays, and memorials, Huan's major work was the Xinlun (新论) or New Discussions, which was admired by Emperor Guangwu despite Huan Tan's besmirched reputation for having closely associated himself with the regime of the usurper Wang Mang.
[1] His Xinlun is also the earliest text to describe the trip hammer device powered by hydraulics (i.e., a waterwheel), which was used to pound and decorticate grain.
He drew explicitly on Legalism in his writings on government, saying that in certain historical epochs harsher punishments are needed.
On one hand, he is quoted to say that "the way of immortals" is a fabrication of the lovers for the strange; on the other, however, he was reported to admit the practice as genuine and efficient.