If such be the nature of existence, it could be neither body, nor the substrate of bodies; for their existence is nonentity. (Materialists, however, object), How could we refuse to attribute "being" to the nature of bodies, such as these cliffs and rocks, to the solid earth, and in short, to all these impenetrable objects? When I am struck, am I not by the shock forced to acknowledge that these objects exist as (real) "being"? On the other hand, how does it happen that entities that are not impenetrable, which can neither shock others nor be shocked by them, which are completely invisible, like soul and intelligence, are genuine beings?[51] Our answer is that the earth, which possesses corporeal nature in the highest degree, is inert; the element that is less gross (the air) is already more mobile, and resides in a higher region; while fire withdraws still more from corporeal nature. The things which best suffice themselves least agitate and trouble the others; those that are heavier and more terrestrial, by the mere fact that they are incomplete, subject to falling, and incapable of rising, fall by weakness, and shock the others by virtue of their inertia, and their weight. Thus inanimate bodies fall more heavily, and shock and wound others more powerfully. On the contrary, animated bodies, by the mere fact of greater participation in existence, strike with less harshness. That is why movement, which is a kind of life, or at least an image of life, exists in a higher degree in things that are less corporeal. CORPOREITY IS NONENTITY BECAUSE OF LACK OF UNITY. It is therefore an "eclipse of existence" which renders an object more corporeal. While studying those psychoses called affections, we discover that the more corporeal an object is, the more is it likely to be affected; the earth is more so than other elements, and so on. Indeed, when other elements are divided, they immediately reunite their parts, unless there be some opposition; but when we separate parts of earth, they do not come together again. They thus seem to have no natural earth; since, after a light blow, they remain in the state where they are left by the blow that struck or broke them. Therefore the more corporeal a thing is, the more it approaches nonentity, returning to unity with the greater difficulty. The heavy and violent blows by which bodies act on each other are followed by destruction. When even a weak thing falls on something weak, it may still be relatively powerful; as is nonentity hitting nonentity. SENSATION AS THE DREAM OF THE SOUL FROM WHICH WE MUST WAKE.