Averroes's theory of the unity of the intellect
Averroes expounded his theory in his long commentary on Aristotle's On the Soul to explain how universal knowledge is possible within the Aristotelian philosophy of mind.
[2] Plotinus (d. 270), whose works were well known in the Islamic world, proposed that human beings gained knowledge through their relation to a divine intellect.
[2] Muslim philosophers Al-Farabi (d. 951) and Avicenna (also known as Ibn Sina, d. 1037) further develop this theory and call it the "agent intellect", which gives forms to matter and facilitates human knowledge.
He provides different theses for explaining human knowledge in his previous two commentaries, suggesting that the notion of unity of the intellect is his most mature theory after having considered other ideas.
[5] Another Averroist, John Baconthorpe proposed that there is an ontological and an epistemological aspect of the union between the unique intellect and the body, developing a theory that is called the "double conjunction" (Latin: copulatio bifaria).
[5][2] Many, especially the Averroists, saw appeal in the theory because it explained universal knowledge and justified Aristotle's idea of the intellective soul.
[5] The Italian poet Dante Alighieri (c. 1265 – 1321) used Averroes's theory as a basis for his secularist political philosophy in the treatise De Monarchia.
[10] He argued that given that all mankind shares one intellect, men should be politically united to achieve their highest goals, universal peace and happiness on earth.
[6][5] Thomas Aquinas wrote a treatise De Unitate Intellectus, Contra Averroistas ("On the Unity of the Intellect, against the Averroists"), which contained detailed arguments to reject this theory.
