In 1670, he was promoted to the rank of jinshi and moved to Beijing, leaving his brother Li Guangpo behind to look after his family.

[2] Later in life, he was responsible for planning Shi Lang's conquest of Taiwan.

He also highlighted similarities between the teachings of Confucius and those of Buddha and Lao Tzu.

[4] Li wrote or edited a number of philosophical texts, including the Complete Works of Master Zhu (Zhuzi daquan), the Essential Ideas of Nature and Principle (Xingli jingli) and the Interpretation of the Meaning of the Four Books (Si shu Jieyi).

An expert on the I Ching, he also wrote two books on the subject, the Penetrating Discourse (Zhouyi tonglun) and the Balanced Annotations (Zhouyi zhezhong); the latter took the (at the time) unusual editorial step of segregating the original text of the I Ching from its subsequent commentaries.