MIND AND SOUL think that an agent intellect was required at all The Aristotelian answer would be that the material objects of the world we live in are not, in themselves, Wt objects for intellectual understanding The nature and characteristics of the objects we see and feel are all embedded in matter: they are transitory and not stable, individual and not universal They are, in Aristotelian terms, only potentially thinkable or intelligible, not actually so To make them actually thinkable, it is required that abstraction be made from the corruptible and individuating matter, and concepts be created that are actually thinkable objects That is the function of the agent intellect Al-Farabi compares the action of the agent intellect upon the data of sensory experience to the action of the sun on colours Colours, which are only potentially visible in the dark, are made actually visible by the sunlight Similarly, sense-data that are stored in our imagination are turned by the active intellect into actually intelligible thoughts The agent intellect structures them within a framework of universal principles, common to all humans (Al-Farabi gives as an instance ‘two things equal to a third are equal to one another’.) Thus far al-Farabi’s account seems philosophically plausible The diYcult point—and one that was to be debated for centuries—is whether the agent intellect is to be identiWed with some separate, superhuman entity, or whether it should simply be regarded as a species-speciWc faculty that diVerentiates humans from nonlanguage-using animals Al-Farabi’s Muslim successors emphasized, to an ever greater degree, the superhuman element in intellectual thought For Avicenna, as for alFarabi, the First Cause is at the summit of a series of ten incorporeal intelligences, each giving rise to the next in the series by a process of emanation, of which the tenth is the agent intellect The agent intellect, however, has for Avicenna a much more elaborate function than it has for al-Farabi: it is a veritable demigod First it produces by emanation the matter of the sublunar world, a task that al-Farabi had assigned to the celestial spheres; that is to say, it is responsible for the existence of the four elements Next, the agent intellect produces the more complex forms in this world, including the souls of plants, animals, and humans Indeed the ‘giver of forms’ is one of Avicenna’s favourite titles for the agent intellect Once again, we encounter emanation: forms that are undiVerentiated within the agent intellect are transmitted, by necessity, into the world of matter Only at a third stage does the agent intellect exercise the function 224