The author focuses on one of the most fascinating texts of the 17th and 18th century China mission – the Tianxue benyi 天學本義 (The Original Meaning of the Heavenly Teachings) and the more elaborate Gujin jingtian jian 古今敬天鑒 (Mirror on the Worship of Heaven in Ancient Times and Nowadays), both written and compiled by the Jesuit Joachim Bouvet (1656–1730) with the assistance of Chinese converts.
