Compendium on the Soul

O i

Similarly, in the movements of the sensory soul The "sensory soul" refers to the part of the soul responsible for perception and movement, shared by humans and animals that are not excessive, and involving a sensible object that is not overpowering, there is no "inhibitor" original: "prohibens" that falls upon it to weaken the soul’s sensory or motive powers, nor their operations. On the contrary, the powers of the soul—and its movements and operations, both motive and sensory—are actually perfected when they are performed in a moderate way with a moderate object.

Therefore, in the movements of the soul, there is no such "inhibitor" as described before, unlike what occurs in the elements and in their qualities when they act upon one another. If the soul were merely some quality of the elements (in which such inhibitors do occur), one would have to ask why and how that soul would necessarily possess that which requires the aforementioned inhibitor. That is to say: how would a weakening of the soul's operations necessarily be caused by that inhibitor—specifically from the weakening of qualities original: "refractione qualitatum," referring to the way qualities like heat and cold temper or "break" each other's strength when mixed which demands such a weakness of operations?

Since no way can be found to show how this weakness of operations is caused in the movements of the soul by such an inhibitor, it follows that in the soul—which has its own operation by itself, or is a thing existing by itself original: "res una per se"—no such inhibitor falls. For this reason, the soul is not some quality of the elements, nor any form of them, nor does it lean toward any one of them.

By "a thing existing by itself," one can understand a substance that exists on its own, in which no weakening or lessening original: "refractio & remissio" occurs, as happens in active and passive qualities. Alternatively, it can be understood as a thing existing by itself that is not mixed with another, nor is it dependent on another thing for its being or its preservation. This "thing existing by itself," when defined in the first way, is true of any soul; but when defined in the second way, it is true specifically of the intellective soul The "intellective soul" is the human rational mind, which Avicenna argues can exist independently of the body.

And the phrase WHY WOULD IT BE NECESSARY etc. means that if the soul leaned toward some form of the elements and used a quality proper to that elemental form in its operations, it would then only move toward one part Meaning it would only move in one natural direction, such as down for earth or up for fire. And if that were so, why then would that which the inhibitor requires be necessary alongside the movements of the soul? For such an inhibitor would cause weakness in the movement produced by those elemental forms.

Therefore, to clarify this, it should be known that in a human being there are two species of movement. One comes from the nature of the dominant heavy element, namely, moving downward. The other species of movement in a human is different from the movement produced by the dominant, heavy element. This type of movement is progressive movement Walking forward or leaping upward. Such movement is produced by the soul, which at times actually makes the body less heavy (as is clear from experience) and resists the gravity of the human body.

In a human, therefore, it is the soul that inhibits or weakens the downward movement of the person, so that they do not move downward so quickly or so heavily. If, then, the soul in a human or another animal leaned toward some form of the elements and used the qualities proper to an elemental form in its operations, the soul would move only toward one part, and there would be nothing in the human to inhibit or weaken the downward movement. If the soul belonged to that first division—namely, leaning toward some form of simple elements—then one would have to ask why that which the inhibitor requires would be necessary...