in what they said concerning both definition and syllogism, just as they expose their errors in metaphysics and other subjects. None of the Muslim scholars engaged in rational inquiry paid heed to their method. Rather, the Ashʿarīs, Muʿtazilah, Karrāmiyyah, Shīʿah, and all the other groups engaged in rational inquiry criticized it and demonstrated its unsoundness. The first to mix their logic with the foundational principles of the Muslims was Abū Hāmid al-Ghazālī. Muslim scholars criticized him in terms that would take too long to recount.
Such refutations of them appear in many works of speculative theology. The book al-Ārā wa-l-Diyānāt (Opinions and Religions), by Abū Muhammad al-Hasan ibn Mūsā al-Nawbakhtī, contains a good section on this subject. After describing Aristotle’s method in logic, he said:
“Some Muslim speculative theologians objected to these formulations of logic, saying that the logician’s claim that a syllogism cannot be constructed from a single premise is mistaken. For example, someone wishing to establish that a human being is a substance can argue directly for the very point at issue without first setting out two premises. He can say: ‘The proof that a human being is a substance is that he admits contrary attributes at different times.’ He has no need of a second premise, namely: ‘Everything that admits contrary attributes at different times is a substance.’ For the particular is included in the general, so whichever of the two he establishes, he has no need of the other. Likewise, when a person observes an effect, he may infer that it has a cause, and when he observes writing, that it has a writer, without needing two premises to establish the validity of that inference.