It is certain that there is in the universe a very subtile spirit, or a very delicate matter, and always in motion, the source of which is in the Sun, and the remainder is spread in all the other bodies, more or less, according to Nature or their consistency. That is the Soul of the Universe which governs and vivifies it, and of which some portion is distributed among all the parts that compose it. This Soul, and the most pure Fire which is in the universe does not burn of itself, but by the different movements that it gives to the particles of other bodies where it enters, it burns and reflects its heat. The visible fire has more of this spirit than air, the latter more than water, and the earth much less than the latter. Among the mixed bodies, plants have more than minerals, and animals more than either. To conclude, this fire being enclosed in the body, it is rendered capable of thought, and that is what is called the soul, or what is called animal spirits, which are spread in all parts of the body. Now, it is certain that this soul being of the same nature in all animals, disperses at the death of man in the same manner as in other animals, from whence it follows that what Poets and Theologians sing or preach of the other world, is a chimera which they have invented, and which they narrate for reasons that are easy to guess.
OF SPIRITS WHICH ARE CALLED DEMONS.
I.
We have fully commented on how the belief in Spirits was introduced among men, and how these Spirits were but phantoms which existed in their imagination. The ancient Philosophers were not sufficiently clear to explain to the people what these phantoms were, and did not allow themselves to say that they could raise them. Some seeing that these phantoms dissolved and had no consistency, called them immaterial, incorporeal, forms without matter, or colors and figures, without being, nevertheless, bodies either colored or defined, adding that they could cover themselves with air like a mantle when they wished to render themselves visible to the eyes of men. Others said that they were animated bodies, but were composed of air, or some other more subtile matter which condensed at their will when they wished to appear.