This article explicates Averroes's understanding of human knowing and abstraction in this three commentaries on Aristotle's De Anima. While Averroes's views on the nature of the human material intellect changes through the three commentaries until he reaches is famous view of the unity of the material intellect as one for all human beings, his view of the agent intellect as 'form for us' is sustained throughout these works. In his Long Commentary on the De Anima he reveals his dependence on al-Fârâbî for this notion and provides a detailed critique of the Farabian notion that the agent intellect is 'form for us' only as agent cause, not as our true formal cause. Although Averroes argues that the agent intellect must somehow be intrinsic to us as our form since humans are per se rational and undertake acts of knowing by will, his view is shown to rest on an equivocal use of the notion of formal cause. The agent intellect cannot be properly our intrinsic formal principle while remaining ontologically separate.