Aristotle gives his most substantial account of the passive intellect in ''De Anima, Book III, chapter 4. In Aristotle's philosophy of mind, the passive intellect "is what it is by becoming all things." By this Aristotle means that the passive intellect can potentially become anything by receiving that thing's intelligible form. The active intellect is then required to illuminate the passive intellect to make the potential knowledge into knowledge in actuality, in the same way that light makes potential colors into actual colors. The analysis of this distinction is very brief, which has led to dispute as to what it means.
Interpretations
Greek thought While Greek commentators such as Alexander of Aphrodisias and Themistius were broadly silent on the active intellect, they provided a great deal of commentary on the nature of the passive intellect. For Alexander of Aphrodisias, for instance,, the passive intellect was a separate intellect from the active. Averroes and Aquinas Later philosophers, including Averroes and St. Thomas Aquinas, proposed mutually exclusive interpretations of Aristotle's distinction between the active and passive intellect. Other terms used are "material intellect" and "potential intellect", the point being that the active intellect works on the passive intellect to produce knowledge, in the same way that actuality works on potentiality or form on matter. 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. Aquinas argues against this position in the Disputed Questions on the Soul, and asserts that while the passive intellect is one specifically, numerically it is many, as each individual person has their own passive intellect.
Passive intellect is identical with Aql Bil Quwwah in Islamic philosophy. Aql bi-al-quwwah, defined as reason, could abstract the forms of entities with which it is finally identified. For Farabi, the potential intellect becomes actual by receiving the form of matter. In other words, Aql Hayulany tries to separate the forms of existents from their matter. The form become identical with Aql. Farabi also recognised the potential intellect as part of soul.
