Al-Fārābī on Existential Import: Empty Terms and Category Mistakes

In al-Maqūlāt, al-Fārābī provides a systematic examination of all categorical propositions, with an existent subject or a nonexistent one. His analysis shows that he attributes an import to all affirmative propositions and denies it from all negative ones, thus generalizing Aristotle’s view about singular propositions to all other kinds of propositions. He also explicitly evokes empty terms and provides an explicit account of what Gilbert Ryle, nowadays, calls “category mistakes.” However, we find some confusion in his text, for he sometimes expresses O as “Some A is not B” and uses ekthesis in his proof of Baroco, which could suggest that O has an import. In addition, he holds contraposition but expresses it in a way that seems incompatible with the import of A propositions. In this article, I wish to show that these confusions do not make al-Fārābī’s opinion about existential import inconsistent; rather, it is only insufficiently clear. As for his view about category mistakes, it is more precise than Aristotle’s brief account; but the topic is not treated at length as it is in contemporary analyses. A translation of the relevant passages of al-Maqūlāt is added as an appendix.