Aristotle gives his most substantial account of the passive intellect (nous pathetikos) in De Anima (On the Soul), Book III, chapter 4.
"[1] By this Aristotle means that the passive intellect can potentially become anything by receiving that thing's intelligible form.
[citation needed] Averroes held that the passive intellect, being analogous to unformed matter, is a single substance common to all minds, and that the differences between individual minds are rooted in their phantasms as the product of the differences in the history of their sense perceptions.
[citation needed] Passive intellect is identical with Aql bi al-Quwwah in Islamic philosophy.
Aql bi-al-Quwwah, defined as reason, could abstract the forms of entities with which it is finally identified.