The second view is that these are self-subsistent substances, like the rational soul—a position favored by Ibn Sīnā and others, though its details are treated elsewhere.

What concerns us here is their claim that, once it departs from the body, the rational soul subsists merely as an intellect, possessing no desire, will, or love for knowledge at all; this, in their eyes, is the height of perfection. For that reason, when Abū al-Barakāt set out their doctrine he clarified the matter, saying:

“Chapter Two: On the opinion of Aristotle and his followers concerning the beginning of creation. He states that whoever reflects upon his words will see that the God from whom creation originated is One in every respect; no multiplicity attaches to Him whatsoever. From the One only one can proceed. Thus the first creature among all existents is a single being, the closest of them to Him and the most resembling Him. I call it ‘Intellect.’ The sense of ‘intellect’ here is understood by comparison with the human soul, inasmuch as it is a spiritual, not corporeal, substance—like the soul. The soul, however, is linked to the body: the individual human soul, the soul of the celestial sphere, and the soul of the star that impels that sphere, for it directly effects motion. The Intellect, by contrast, is free of bodies and their attachments. The soul functions as a power insofar as it moves bodies and alters their states, and thus it is aware of the ever-renewed conditions that arise within them …”