The Summary of Physics Restored

81The leading figures of ancient philosophy placed fire, as nature's fourth element, in the highest region of air as in a sphere of its own. This seemed right to them for the sake of order and through conjecture rather than through the light of truth. For no one should imagine a fire of nature other than celestial light. The sacred philosopher therefore makes no mention of fire in his Genesis, because he had said that light, which is nature's true fire, was created on the first day. Nor would he have omitted fire as a principle of nature when he mentioned earth, water and the birds of heaven.