[15] Cf. my Article “On Kindi and his School” in Stein’s ‘Archiv für Geschichte der Philosophie XIII’, p. 153 sqq., from which I have taken over, without much alteration, not a little that appears in this chapter. [16] [Translator’s note.—The Bagdad Caliphate lasted up to the death of Mustassim (A.H. 656 or A.D. 1258), i.e. for 400 Mohammedan years after A.H. 256 or A.D. 870]. [17] The Arabic ʻaql (νοῦς) is usually translated by Reason and Intelligence (Lat. intellectus and intelligentia). I prefer however the rendering, Geist, Spirit or Mind, because the expression includes God and the pure (separate) spirits of the spheres. Moreover it is hard to decide how far the personification of Reason was carried by individual thinkers. [18] [Translator’s note.—Accordingly Ibn Sina’s Five Internal Senses are: A. The General or Co-ordinating Sense; 2. Memory of the Collective sense-images; 3. Unconscious Apperception, referring to individuals; 4. Conscious Apperception, with generalization; 5. Memory of the higher apperceptions]. [19] “Averrois, che’l gran comento feo” Canto IV. [20] Ibn Khaldûn speaks only of rich people who have grown poor, and says nothing of the misery of the proletariate, and that which prevails in large cities, as we know it. He lived too in smaller cities, for the most part, and till late in life admired Cairo from a distance.