NATURE IS IMMOVABLE AS A FORM, BUT NOT AS COMPOUND OF MATTER AND FORM.
It may be objected that the ("seminal) reason" may remain immutable, but that nature is distinct from reason, and is mutable. Considering the totality of nature, we include reason. Considering only one of its parts as immutable, this part still will be reason. Nature must be a form, and not a composite of matter and form. What need would it have of a matter that might be either cold or hot, since matter, when subjected to form, either possesses these qualities, or receives them, or rather undergoes the action of reason before having any qualities. Indeed, it is not by fire that matter becomes fire, but by reason. Consequently, in animals and plants, it is the "reasons" that produce[180]; and nature is a reason that produces other reasons, imparting some of herself to the substance subjected to her influence, while remaining within herself. The reason that consists in a visible shape occupies the last rank; it is dead, and produces nothing. The living "reason" (which administers the body of the living being), being sister to the "reason" that produced the visible form (in begetting the body of the living being), and possessing the same power as this reason, alone produces within the begotten being.[181]