AVICENNA

Alternative reading: A. The element follows from this, because the power of one element dominates.

The cause of their motion arises through a progression, by which an impression is produced by an agent. Since this is manifest to us, let us say that we find certain bodies generated from the four elements The classical elements: Earth, Water, Air, and Fire which are moved non-violently by two types of motion, between which there is some diversity, or by two distinct types of motion. One of these [is inherent to the essence or the nature of the composition because of the dominance of the power of one of the elements] over them, and its requirement or its inclination to move toward the place or the "where" assigned to it by nature—just as the motion of a man follows the nature of the dominant heavy element descending downward Referring to the tendency of "heavy" elements like earth to move toward the center of the universe. And this species of motion is found in only one mode and toward one direction.

The second species of motion is different from that which the [essence or the aforementioned composition requires. This composition either requires] rest in its natural place at the time it is united with it. And [this second species of motion] is like when a man moves his body within his natural place, which is the surface of the earth. Or [the aforementioned essence or composition] requires or seeks motion toward a natural place when it is outside of that natural place. An example of this second species of motion, which differs from this requirement, is like the motion of an animal flying with its heavy bulk upward into the air.

It appears, therefore, that for these two motions there are two different instruments or two different causes: one of which we call nature, and the second we call the soul original: "anima", or the animal power animal power: the faculty that allows for voluntary movement and sensation, as opposed to mere physical growth. It has now been verified, therefore, from the perspective of motion, that the soul exists, or that the existence of the powers of the soul is found.

Furthermore, this same point is demonstrated from the perspective of perception original: "apprehensio", since bodies are found that share the quality of being a "body" but differ in that some are capable of perception. From the first principle or the first discourse, it is manifest that perception does not proceed from them by themselves, but rather through a principle or through a moving power within them. Therefore, from this mode of demonstration, the discovery or the existence of the powers of the soul appears; and this is what we wished to declare.