Scholars on studying logic

1Why the question arose

Logic came into Arabic with the translations of Greek philosophy, and for a long time it was taught together with philosophy. For its defenders it was a neutral tool, a set of rules for correct thinking that any science could use. For its critics it was the doorway through which the philosophers’ doctrines on God, the world and the soul entered Muslim thought.

Because of this debate, later primers treat the “ruling” (ḥukm) of logic as one of the ten things a student should know before starting a science, the ten principles (al-mabādiʾ al-ʿashara) explained on The Mantiqi. Al-Abharī’s Īsāghūjī itself does not raise the question; it simply presents logic as something every beginner in the sciences needs. The debate is recorded in the commentaries and, above all, in al-Akhḍarī’s verse version.

2Al-Ghazālī: a tool every scholar needs

The most influential Sunni endorsement came from al-Ghazālī (d. 505/1111). He wrote several handbooks of logic (Miʿyār al-ʿilm, Miḥakk al-naẓar, al-Qisṭās al-mustaqīm) and opened his late work on legal theory, al-Mustaṣfā, with a long introduction on logic. There he calls it the introduction to all the sciences and says that the knowledge of someone who has not mastered it cannot be relied upon at all.

In his autobiography, al-Munqidh min al-ḍalāl, he separates logic from the philosophers’ metaphysics: logic in itself neither affirms nor denies anything in religion. In his own logic books he used terms and examples from law and theology, so that logic would look like a native Muslim discipline. Modern historians credit him, and later Fakhr al-Dīn al-Rāzī, with making logic a recognised tool for jurists and theologians; after them, works on theology and legal theory often began with a chapter on logic.

3Ibn al-Ṣalāḥ and al-Nawawī: prohibition

A century later the Damascene hadith scholar Ibn al-Ṣalāḥ (d. 643/1245) was asked about people who studied and taught philosophy and logic. In his fatwa he called philosophy “the head of folly and dissolution”, said that logic “is the entrance to philosophy, and the entrance to evil is evil”, and ruled that teaching and learning it is not something the Lawgiver has permitted. Those who taught it, he said, should be removed from the madrasas, and according to the TDV İslâm Ansiklopedisi the rulers of Damascus followed his view for years.

Al-Nawawī (d. 676/1277), who later headed the same Dār al-Ḥadīth al-Ashrafiyya and was the greatest Shāfiʿī authority of his time, is reported to have followed him in this; that is how al-Akhḍarī names the two together. The text in which al-Nawawī states his view is not identified in the sources consulted here.

How much weight these fatwas carried is itself debated. Ignaz Goldziher read them as making logic a forbidden science; Khaled El-Rouayheb (2004) argued that this reading is mistaken and that between 1500 and 1800 opposition to logic was marginal. A recent Arabic defence of Ibn al-Ṣalāḥ (Muḥammad Abū al-Fatḥ, 2025) argues, on the other hand, that his ruling was general and not limited to logic mixed with philosophy, and that it rested on the principle of blocking the means to harm.

4Ibn Taymiyya’s critique

The Ḥanbalī theologian Ibn Taymiyya (d. 728/1328) went further than a fatwa. In al-Radd ʿalā al-manṭiqiyyīn (“Refutation of the Logicians”), begun under house arrest in Alexandria in 1309–1310, he attacked Aristotelian logic as reworked by Ibn Sīnā on its own ground.

He argued that definitions are matters of linguistic convention that distinguish things rather than reveal their essences, and give no knowledge one did not already have; that the syllogism is valid but its many figures and conditions are “prolixity of little use and much weariness”, and that certain knowledge is often reached without it; that analogy and the categorical syllogism are equivalent; and that universals exist only in the mind. His critique was later abridged and reorganised by al-Suyūṭī (d. 911/1505), who also opposed logic and treated it as an innovation; the English translation by Wael Hallaq (1993) is of this abridgement.

According to Jon Hoover, logicians of his own time and later paid the Refutation little attention, partly because it did not engage with the newer logic of his day. Its modern influence has been far greater, since Ibn Taymiyya became a major inspiration for Salafism.

5Al-Akhḍarī’s three positions

The classic summary of the debate is in al-Akhḍarī’s versification of the Īsāghūjī, al-Sullam al-munawraq (ca. 941/1534): “The disagreement over whether one may study it takes three positions: Ibn al-Ṣalāḥ and al-Nawawī forbade it; some said it should be learned; and the well-known, correct position is that it is permitted to one of sound mind who is practised in the Sunna and the Book, so that he may be guided by it to what is right.”

The third position sets conditions rather than giving a blanket permission. The Shāfiʿī jurist Tāj al-Dīn al-Subkī, in a fatwa quoted by later authors, required that the student first be grounded in the Qurʾān, the Sunna and law, and warned that logic can breed arrogance and, in those without a firm foundation, lead toward the philosophers’ beliefs; but he compared it to a sword, which one person uses in God’s cause and another to rob travellers.

Commentators on the Sullam added a further distinction. Aḥmad al-Damanhūrī (1690–1778) wrote that the disagreement concerns only logic mixed with the philosophers’ teachings; the logic used in the scholars’ own books is not disputed. Aḥmad al-Mallawī (d. 1181/1767) said the same. On this reading, the Īsāghūjī and the Sullam themselves, which contain no metaphysics, fall outside the prohibition.

6Acceptance in the madrasas

In practice the third position prevailed among Ashʿarīs and Māturīdīs. According to El-Rouayheb, mainstream scholars in the Maghrib, Egypt and Turkey between 1500 and 1800 regarded logic as commendable, some even as a religious duty. The Shāfiʿī Ibn Ḥajar al-Haytamī (d. 973/1566) cited al-Ghazālī’s endorsement in a fatwa; the chief judge Zakariyyā al-Anṣārī wrote one of the standard commentaries on the Īsāghūjī; and the theologian al-Sanūsī wrote a logic handbook that was standard in Cairo.

Among Ottoman Māturīdīs, scholars such as Saçaklızâde and Dāwūd Qārṣī criticised the way logic was taught, with too many glosses too early, but neither rejected the study of logic itself. The curricula described in the previous article, from Istanbul to Delhi and Madura, show how firmly the Īsāghūjī and the Sullam were established.

7Modern views

In modern times the debate has revived. El-Rouayheb notes that opposition to logic has been strengthened by the rise of Salafism, which draws heavily on Ibn Taymiyya, and some preachers today condemn logic outright. Others answer from within the tradition: ʿAlī Jumʿa, former Grand Mufti of Egypt, holds in a fatwa that pure logic is a neutral tool, recommended for students of the religious sciences and a collective obligation for those who defend Islam, and that blame applies only to logic mixed with philosophical errors or to its misuse.

Between these positions, some writers argue that blanket bans ignore the reasoning of the early critics, who targeted the metaphysics bound up with Greek logic rather than the discipline as such, and point out that legal theory (uṣūl al-fiqh) shares many concepts with logic.

Academic historians have also changed their view. Older scholarship, following Ignaz Goldziher, tended to treat religious hostility to logic as decisive. Recent work, notably by El-Rouayheb, argues that such opposition was the exception rather than the rule after 1500, and shows that primers like the Īsāghūjī, through their commentaries and glosses, were the entry point to very advanced debate.