Telesio, Aristotle, and Hippocrates on Cosmic Heat

The faculty of the soul of every kind has to do with a matter different from and more divine than the so-called elements. But as one soul differs from another in the scale of value, so does the nature of the corresponding matter. In every seed there is that which causes it to be fertile, that is, what is called “heat.” This heat is neither fire nor any such faculty but the pneuma which is enclosed in the seed and a foam-like body. Nature in this pneuma is analogous to the element of the stars. That is why fire does not generate any animal, and we find no animal taking shape in either fluids or solids under the influence of fire; whereas the heat of the Sun and that of animals do generate them. Not only the heat residing in the seed but also whatever other natural residue, which there may be, has in itself a vital principle too. Considerations of this sort clearly show us that the heat contained in animals neither is fire nor draws its origin from fire.1