 In any case the only kind of justification that al-Fārābī offers for logical rules is that they have been found useful for certain purposes in the community that uses them (cf.  Section 3 above).  All in all, al-Fārābī treats the formal rules of logic as heuristics rather than as laws of a scientific theory. A case can be made for viewing al-Fārābī as one of the creators of what is now known as “informal logic”, as in the texts of Hitchcock (2017) and Walton (1989). The pivotal role that he gives to dialogue places him in the same world as Walton’s book.