Shared Ideas, Divergent Approaches: The Hydromethods of the Great West (Taixi shuifa 泰西水法) and the Question on Tides

One of the questions about natural phenomena asked in the Hydromethods of the Great West (Taixi shuifa 泰西水法; 1612) (hereafter TXSF), composed by the Italian Jesuit Sabatino de Ursis with the support of the Chinese official Xu Guangqi 徐光啟, concerns the causes of sea tides. The idiosyncratic answer given in the TXSF serves as an example for the Jesuit missionaries’ strategically motivated approach to the transfer of knowledge through the translation of Western scientific thought into Chinese. From a chronological overview of the attempts made both in the East and in the West to theoretically conceptualize the causes of the cyclical occurrence of ebb and flow, the comparison reveals that despite being based on totally different cosmologies, the related insights were virtually on a par. The aim to nevertheless convince the audience of the TXSF of the superiority of Western sciences resulted in a particular rhetoric and a division of tasks in the composition of the tides paragraph. In order to verify the success of this joint effort of de Ursis and Xu Guangqi, a change of perspective from the transmitter to the receiver side is necessary. Thus, the paper also explores the work’s reception in later Chinese works dealing with this topic.