 Al-Fārābī’s treatment of information-seeking questions is strongly influenced by two contexts in which Aristotle’s Organon uses question words. The first of these is in Categories, where Aristotle (at least as al-Fārābī reads him) classifies primary concepts under the ten supreme genera. Aristotle explains his classification partly through question words: “how much” (Arabic kam), “how” (kayfa), “where” (ayna), “when” (matā). Al-Fārābī takes note of most of these question words, and adds two more: “what” (mā) and “which” (ayyu) ([Letters] (166) 165.17, (183) 181.16.) In [Expressions] 47.5–12 he notes that the answers to some of these questions can be classified by the question word or a word derived from it: “quantity” (kamiyya), “quality” (kayfiyya), “quiddity” or “whatness” (māhiyya). (See the discussion of these questions in Diebler 2005.)