The Summary of Physics Restored

29All other bodies borrow their light from that luminous torch of the world. Probability suggests that we should believe the other globular bodies have an opacity like that which our senses detect in the moon's globe because of the earth's nearness and the extension of its shadow, though their distance prevents us from perceiving it. For the first and most excellent nature among all sensible things, the source of light, was owed to unity, from which these lower things would receive the breath of life. Hence the philosopher's apt saying: “The sun and a human being generate a human being.”