Tian wen lue (Summary of astronomy) is a well-known work by Yang Manuo, the Chinese name of Father Manuel Dias (1574–1659), also known as Emanuel Diaz. Diaz, a Portuguese Jesuit missionary, arrived in China in 1610 and reached Beijing in 1613. He also spent time in Macao, Shaochuan, Hangzhou, Ningbo, Fuzhou, and other cities. He died in Hangzhou during the reign of the Qing dynasty Shunzhi emperor. Commonly known by its Latin title, Explicatio Sphaerae Coelestis, the book was first published in 1615. This copy is the original edition. It was the first work to introduce to China the telescope, invented and used in astronomical observations a few years earlier by the Italian mathematician and astronomer Galileo Galilei. Galileo supported the heliocentric view of Copernicus, holding that the sun was the center of the solar system, a view for which he was denounced and eventually tried by the Inquisition. Referring to Galileo, Diaz wrote that there was a European who had created a kind of instrument that “watched faraway places as if from nearby.” Although he mentioned the heliocentric theory, Diaz himself was not convinced and still supported the geocentric view. Diaz’s topics were astronomy and science, but his main purpose was to spread Christianity, proclaiming “the basis of knowledge of heaven is morality, and the basis of morality is to know God and serve God.” The book’s Chinese title, Tian wen lue, originated from Tian wen, the Chu poetry anthology by poet Qu Yuan (circa 340–278 BC). While Qu Yuan believed in nine spheres of heaven, Diaz introduced the 12 divisions. Following the Jesuit missionary Matteo Ricci’s method of explaining Christian concepts in terms familiar to the Chinese and taking into consideration the Chinese people’s familiarity with the nine spheres of heaven, Diaz repackaged and promoted the unfamiliar astronomy and religion by placing God in the 12th division, called Mountain of Paradise, thus in a visual and symbolic way strengthening the Chinese reader’s knowledge of God and Paradise. Written in the form of questions and answers to the Chinese queries, the book was studied and reissued into the 19th century.