The ArgumentThis paper examines the debate in China over the shape of the earth during the seventeenth and eighteenth centuries. The main arguments are as follows. First, trust plays an important role in knowledge transmission. Second, partial communication between different woridviews is possible. In the case of the debate over the shape of the earth, partial communication was accomplished by the spread of Western astronomical instruments and calculating tools. Third, such alien concepts as the four elements and the experience of navigation did not serve as effective cultural resources to convince Chinese literati of the sphericity of the earth. Fourth, as a result, the legitimacy of the sphericity of the earth had to be reconstructed in an alien environment. The theory of the Chinese origins of Western learning was fabricated within such a context. Fifth, debate over factual knowledge bears social and cultural implications. Thus the debate over the sphericity of the earth involved not only how the phenomenon could be understood but also how the Chinese empire was to be positioned in the new cultural atlas. Finally, the sphericity of the earth eventually became a matter of common sense for the Chinese largely because of the political and cultural transformation of modern China.