How the Isagoge travelled

1In the Greek schools of Alexandria

In late antiquity the Isagoge was read at the very start of the philosophy course. Ammonius, son of Hermeias (ca. 435/445–517/526), who taught at Alexandria, set a sequence of introductory lessons: first an introduction to philosophy as a whole, then the Isagoge with a commentary, then an introduction to Aristotle, and only then the Categories. His own commentary is transmitted as the ‘Exegesis of the Five Sayings’ (the five terms).

His successors kept this pattern. Commentaries on the Isagoge survive under the names of Elias and David, both linked to the school of Olympiodorus at Alexandria in the later sixth century, and a further anonymous one now called ‘Pseudo-Elias’. Elias’ commentary is preceded by twelve lectures exhorting the student to philosophy; David’s by an introduction to philosophy, the Definitions and Divisions of Philosophy. Who ‘Elias’ was is uncertain; the Stanford Encyclopedia notes that good evidence for a philosopher of that name is scant and that the Isagoge commentary may record Olympiodorus’ own lectures.

These commentators also handed down the report that Porphyry sent the work to Chrysaorius, and the habit of opening the study of logic with general questions (what philosophy is, what logic is for) before the five terms. The Arabic commentary of Ibn al-Ṭayyib likewise includes such introductory material on the status of logic (Di Vincenzo).

2Into Syriac

In the Near East, Syriac-speaking Christians kept the Alexandrian logic course alive. Under the Umayyad caliphate (661–750) their schools taught a shortened Alexandrian Organon that began with Porphyry’s Isagoge.

According to Sebastian Brock, the Isagoge was the only work of Porphyry translated into Syriac, and two versions survive: an anonymous one from the early sixth century, and a revision made in 645 by Athanasius of Balad, who later became Syriac Orthodox patriarch (684–687) and died in September 687. Syriac scholars, among them Proba, Dionysius bar Ṣalibi and Yawsep II, also wrote commentaries on it.

The HunaynNet project of the Austrian Academy of Sciences publishes the Greek text side by side with both Syriac versions and the Arabic translation, so that the steps of the transmission can be compared.

3Into Arabic

The earliest Arabic contact with the Isagoge is linked to the name Ibn al-Muqaffaʿ. A short compendium of logic, which begins with an Isagoge and continues with the Categories, On Interpretation and Prior Analytics, is ascribed either to the famous secretary and writer ʿAbd Allāh Ibn al-Muqaffaʿ (d. 139/756) or to his son Muḥammad, active under the caliph al-Maʾmūn. The sources disagree. The historian Ibn al-Qifṭī says Ibn al-Muqaffaʿ made the first Arabic translation, from Persian (TDV); if the father was the translator, the source language would indeed have been Middle Persian (SEP). Other scholars credit the son, and one (Vallat) rejects both attributions. It is also described as a paraphrase rather than a translation.

Several further translations are reported but lost. Ibn al-Nadīm’s Fihrist names a translation from Syriac by a scholar called al-Raqqī; the Turkish encyclopaedia gives his name as Abū l-Qāsim al-Raqqī, while Silvia Di Vincenzo identifies him as Ayyūb ibn al-Qāsim al-Raqqī (d. ca. 840). TDV also mentions a translation by Yaḥyā ibn ʿAdī, and Di Vincenzo considers that Ḥunayn ibn Isḥāq may have made one.

The translation that survives complete is that of Abū ʿUthmān Saʿīd ibn Yaʿqūb al-Dimashqī, a physician and translator in Baghdad in the early tenth century. It was made from Syriac, from Athanasius of Balad’s version, and is preserved in the Paris manuscript of the Arabic Organon (BnF arabe 2346). Aḥmad Fuʾād al-Ahwānī and ʿAbd al-Raḥmān Badawī both edited it in 1952. Ibn Sīnā relied on this translation, and Ibn al-Ṭayyib quotes it in the lemmata of his commentary.

4The first Arabic commentators

Arabic philosophers soon wrote their own works on Porphyry’s subject. Al-Kindī (3rd/9th century) wrote a treatise on the five predicables, now lost, and works on the logical introduction (al-madkhal al-manṭiqī). Al-Sarakhsī (killed 286/899) made an abridgement of Porphyry’s book, and a Kitāb Īsāghūjī is listed under the name of al-Rāzī (TDV).

Al-Fārābī (d. 339/950–1), the leading figure among the Baghdad Aristotelians, wrote a Kitāb Īsāghūjī ay al-Madkhal. It follows Porphyry on the five universals but also briefly treats topics Porphyry only pointed to, such as singular and universal terms, the proposition and definition. The philosopher Ibn Bājja later wrote a commentary (taʿlīq) on it.

In the Baghdad school the Isagoge was also explained phrase by phrase. The long commentary of the Christian philosopher Abū l-Faraj ʿAbd Allāh ibn al-Ṭayyib (d. 1043) survives and has been translated into English by Kwame Gyekye (1979). A Bodleian manuscript once ascribed to al-Fārābī was shown to be his. Ibn Rushd (Averroes, d. 595/1198) wrote an epitome, Talkhīṣ Madkhal Furfūriyūs; its Arabic text is lost, but it survives in a Hebrew translation by Jacob Anatoli, edited by Herbert Davidson in 1969.

5Ibn Sīnā’s al-Madkhal

Ibn Sīnā (d. 428/1037) read Porphyry’s Isagoge as a youth with his teacher al-Nātilī (TDV). In his encyclopaedia al-Shifāʾ (‘The Cure’), whose logic dates from the 1020s, the first book is al-Madkhal, ‘the Introduction’. It follows Porphyry’s topics but is an independent reworking rather than a commentary.

He keeps the five universals within logic, but explains that they matter to logic because they are necessary features of logic’s real subject: ‘second intelligibles’, notions such as universality, genus and subject. In doing so he criticises those who held that logic studies meaningful utterances. He also corrects Porphyry in detail: he rejects one of Porphyry’s definitions of the common accident and distinguishes the accident as a thing (ʿaraḍ) from the accidental as a logical predicate (ʿaraḍī), and he judges the second, comparative part of Porphyry’s book of little use.

Al-Madkhal is the only logical book of the Shifāʾ transmitted in full in both Arabic and a twelfth-century Latin translation. A new critical edition with English translation by Silvia Di Vincenzo appeared in 2021. Ibn Sīnā’s shorter summaries, al-Najāt and al-Ishārāt wa-l-tanbīhāt, also begin with the universals.

6From translation to independent handbooks

After Ibn Sīnā, the reference point of Arabic logic moved from Aristotle and Porphyry to Ibn Sīnā himself. In Tony Street’s words, the Avicennan tradition ‘simply ignored the Aristotelian texts’, and Ibn Sīnā’s work made the Organon irrelevant for most later Arabic logicians.

In the thirteenth century, al-Khūnajī (d. 646/1248–9) wrote his Kashf (‘Disclosure’) on a new model, and his successors wrote compact handbooks. Two of these, al-Abharī’s Īsāghūjī and al-Kātibī’s al-Risāla al-Shamsiyya, became the mainstays of logic teaching in the madrasa from the late thirteenth century to the present, among both Sunnīs and Shīʿīs.

These handbooks no longer comment on Porphyry or on Aristotle. They keep the order Porphyry’s book had set (utterances and the five universals first, then definition, propositions and syllogism), but they are original textbooks, written for students rather than translated for them.

7In the Latin West

In Latin the Isagoge was first translated in the fourth century by the Roman rhetorician Marius Victorinus; that translation is lost. Boethius (d. ca. 524–526) wrote two commentaries on the Isagoge, the first (ca. 504–505) on Victorinus’ version and the second (ca. 507–509) on his own new translation.

Boethius’ translation became a standard textbook in medieval European schools and universities, and his second commentary, with its discussion of Porphyry’s three questions, opened the medieval debate on universals. Peter Abelard and Duns Scotus were among the many later Latin commentators.

The Latin and Arabic traditions grew from the same Greek book but developed separately. They met again in the twelfth century, when Ibn Sīnā’s al-Madkhal was translated into Latin, and much later, in 1625, when the first Latin translation of al-Abharī’s Īsāghūjī was published in Rome (TDV).

8How al-Abharī’s book took the name

Athīr al-Dīn al-Mufaḍḍal ibn ʿUmar al-Abharī (d. 663/1265; some sources give 661/1263) wrote a very short treatise covering the whole of logic. It is also known as al-Risāla al-Athīriyya. It opens its first part, on utterances and the five universals, with the heading Īsāghūjī, and the whole treatise came to be called by that word (see ‘The word Īsāghūjī’).

TDV notes that the book differs in order and content from both Porphyry and Ibn Sīnā; for example, the treatise itself has no chapter on the ten categories. Its brevity and clarity made it the first book of logic taught in the madrasas, and, as Ḥājjī Khalīfa wrote in the seventeenth century, it was the Īsāghūjī ‘well known and in circulation in our time’.

Its commentaries and glosses, beginning with Ḥusām al-Dīn al-Kātī in the fourteenth century, spread across the Islamic world. From that point on, ‘reading the Īsāghūjī’ meant reading al-Abharī, and Porphyry’s title lived on in a book that no longer mentions Porphyry at all.