This was the part of his work on which Bacon most prided himself, and in it, we may add, he seems to owe most to the Arab writers Kindi and Alhazen.
Yusuf al-Kindi, d.
Of the socalled Arabian philosophers of the East, al-Farabi, Ibn-Sina and al-Ghazali were natives of Khorasan, Bokhara and the outlying provinces of north-eastern Persia; whilst al-Kindi, the earliest of them, sprang from Basra, on the Persian Gulf, on the debatable ground between the Semite and the Aryan.
The first of these, Alkindius (see Kindi), flourished at the court of Bagdad in the first half of the 9th century.
Raymond Lully, in a dialogue with an infidel thinker, broke a lance in support of the orthodox doctrine, and carried on a crusade against the Arabians in every university; and a disciple of Thomas Aquinas drew up a list (De erroribus philosophorum) of the several delusions and errors of each of the thinkers from Kindi to Averroes.