From this it is clear that it is on

From this it is clear that it is one thing to give off heal or some kind of influence and another thing to actually heat up or exert that influence on something. For this latter situation requires an object which is receptive to that heat and influence, the former does not, since this effluence can take place without an object, as in the imaginary spaces where the power of the primum mobile probably originates, if one admits that such spaces exist. Further, it is clear that the primum caelum is the first cause of all celestial influences and also the first cause of light and heat since it clearly contains light, heat, and other elemental qualities, for otherwise it would not be divisible into the twelve signs which have different elemental natures.