In various prefatory and introductory materials occupying many pages of the Qiqi tushuo 奇器圖說, a book on Western machines, Wang Zheng 王徵 (1571-1644) laid out his ideas about machines and mechanics. These pages contain discussions of the importance and value of the subject of the book, and show his efforts to legitimize the knowledge of machines and mechanics, which he called “the study of liyi” (liyi zhi xue 力藝之學). In doing that he had to deal with two problems: 1) the problem for a Confucian gentleman to study machines, the “qi 器”, in spite of the general Confucian sentiment that “gentlemen are not ‘qi 器’, mere tools” (Junzi buqi 君子不器); 2) the problem of dealing with knowledge that clearly came from the “Western barbarians.” This paper discusses how he dealt with these problems and tried to establish “the study of liyi” as a respectable and legitimate subject of study.