 Besides the Alexandrian material, al-Fārābī was able to call on highly professional Arabic translations of the books of the Organon. He also had translations of some logical writers from the Roman Empire, such as Alexander of Aphrodisias and Themistius. He is not known to have made any use of earlier Arabic texts relating to logic, such as the Logic of Ibn al-Muqaffa‘ and writings of al-Kindī. (Zimmermann [1981: lxviii–xcviii] and Lameer [1994: Chapter 1] discuss what earlier logical writings were available to al-Fārābī. See also Walzer [1962: 129–136] for al-Fārābī’s sources on Aristotle’s poetics.)