EXPLANATIONS UPON THE COMPENDIUM OF AVICENNA ON THE SOUL, COLLECTED BY ANDREAS OF BELLUNO, PHYSICIAN, FROM ARABIC EXPOSITORS.

Upon the first chapter, concerning the affirmation of the existence of the powers of the soul.

It should be known, according to some, that Avicenna Ibn Sina (c. 980–1037), the Persian polymath whose medical and philosophical works dominated European universities. understands the "essences" of the soul by the "powers" of the soul in this chapter. According to him, the powers of a single soul do not differ from the substance of that soul except by way of consideration A "distinction of reason" rather than a physical or "real" separation.. For just as a point is indivisible, and yet we attribute different things to it—namely, that it is the beginning of one line and the end of another—similarly, different powers are attributed to the soul, which is an indivisible substance. We say it has diverse powers according to how different operations and effects proceed from that same indivisible soul. Consequently, in this place, by "powers of the soul" in an absolute sense, and by its "potencies," we can understand the different substances of the soul: namely, the substance of the vegetative soul, the substance of the sensitive soul, and the substance of the intellectual soul.

Avicenna calls these "powers" because they are something more easily perceived. For from effects, one arrives at the knowledge of powers and potencies; and from such perceived powers, one later arrives at the knowledge of the substance of the single soul, or of the different souls, even if they are not really distinct from the aforementioned potencies and powers. Therefore, in this chapter, Avicenna proves the existence of the powers of the soul so that from the knowledge of their existence—as something more perceptible—one may arrive at certain and demonstrated knowledge: that the soul is something real in the nature of things, not false or imaginary. This is contrary to what the foolish say—that God does not exist because He is not something perceptible by the senses.

But it is argued against the above-written explanation that, according to Avicenna, the power of the soul is not the same as the substance of the soul. For below in the fourth chapter, Avicenna writes in the heading of said chapter: "concerning the division of the vegetative powers, and the account of the necessity of each of them." It is clear, however, that the powers of the vegetative soul are three, and there are not three substances of the vegetative soul in one plant, but only one substance of the soul in which there are three powers or three vegetative potencies: namely, the power of nourishing, the power of growing, and the power of generating its like. These three powers, therefore, differ really from the substance of the soul in the plant; and the same may be said of the other powers of the sensitive soul and the intellectual soul. These powers are indeed distinguished from the soul,