"Wang Xishan....drew on the Tychonic model to construct his own, while pointing to some contradictions in the Jesuits’ writings. The model expounded in Wuxing xingdu jie 五星行度解 (Explanation of the Five Planets’ Angular Motions, 1673), gave a physical, rather than merely geometrical, account of planetary motion: Wang proposed that its cause was an attraction force comparable to that of a magnet"-–Cf. N. Standaert, Handbook of Christianity in China, p. 726.