 The second context is the second book of Posterior Analytics. In the opening lines of this book Aristotle lists the four “things that we seek”, namely that it is so (annahu yūjadu), why it is (li-mādhā), what it is (mā) and which it is (ayyu). In [Letters] (210) 200.16 al-Fārābī adds the question “is it the case that” (hal), which turns Aristotle’s “that it is” into a question.