Chapter 53: On the light of the moon

1. Certain philosophers hold that the moon has a light of its own, that one part of its globe is bright and another dark, and that turning by degrees it assumes different shapes. Others, on the contrary, assert that the moon has no light of its own, but is illumined by the rays of the sun. And therefore it suffers an eclipse if the shadow of the earth is interposed between itself and the sun.