Al-Abharī’s Īsāghūjī

1The book and its names

The book does not give itself a title. After praising God it simply says: “this is a treatise on logic (risāla fī l-manṭiq), in which we have set out what anyone beginning any of the sciences needs to have at hand.” Its first section is headed Īsāghūjī, the Arabic form of the Greek eisagōgē, “introduction”, the title of Porphyry’s famous introduction to Aristotle’s logic. That heading became the name of the whole work. In the edition used on The Mantiqi, too, the first section opens with the word Īsāghūjī.

It is also known as al-Risāla al-Athīriyya fī l-manṭiq, “Athīr’s treatise on logic” (in Ottoman Turkish Risâle-i Esîriyye), after the author’s honorific Athīr al-Dīn, and as Īsāghūjī fī l-manṭiq or Kitāb al-Īsāghūjī. Under the name Isagoge it was printed in Rome in 1625 with a Latin translation.

The title has led to some confusion. Because Porphyry’s Isagoge was a short introduction to the five universals, al-Abharī’s book is sometimes described as an Arabic adaptation of, or commentary on, Porphyry. Encyclopaedia Iranica calls it a “popular Arabic elaboration” of Porphyry’s work; Hüseyin Sarıoğlu and other recent scholars stress that it is an independent work and neither an abridgement nor an adaptation. It shares Porphyry’s subject only in one of its seven parts; the rest covers the whole of logic.

2When it was written

No date of composition is recorded. Asadollah Falahi, who has studied al-Abharī’s earliest logic works, counts the Īsāghūjī among his first four logic treatises and suggests, as a hypothesis based on its content, a date around 620/1223. Manuscript notes indicate that al-Abharī taught these early treatises to his student Najm al-Dīn al-Kātibī in 627/1230.

One argument for an early date is that some formulations in the Īsāghūjī are corrected in al-Abharī’s later works. Falahi notes, for example, that its definition of conversion speaks of keeping affirmation and negation, where the correct condition is keeping truth. (The text printed in the edition used on The Mantiqi mentions both.) Manuscripts of a text this widely copied are not all the same, and such small differences between copies are to be expected.

The Īsāghūjī belongs to the generation of logicians after Fakhr al-Dīn al-Rāzī (d. 606/1210). Like al-Kātibī’s al-Risāla al-Shamsiyya and al-Urmawī’s Maṭāliʿ al-anwār, it is one of the handbooks through which the logic of Ibn Sīnā, as reworked by these later authors, spread across the Islamic world. Falahi names Afḍal al-Dīn al-Khūnajī as the strongest influence on al-Abharī’s logic.

3What it contains

After the short preface, the text on The Mantiqi (59 numbered segments) falls into six parts. The first is about utterances: how a word signifies its meaning by correspondence, by inclusion or by implication (the example is “human” and “rational animal”); simple and composite utterances; universal and particular ones. The second sets out the five universals: genus, species, differentia, proprium and common accident, with stock examples such as “laughing” for the proprium and “breathing” for the common accident.

The third part is on definition (the “explanatory statement”): the complete and incomplete essential definition (ḥadd) and the complete and incomplete descriptive definition (rasm). The fourth, the longest, is on propositions: categorical and conditional propositions (connective and disjunctive), affirmative and negative, singular, quantified and unquantified; then contradiction, with its conditions of unity in subject, predicate, time, place and so on, and conversion.

The fifth part is on the syllogism. It defines it, distinguishes the conjunctive and the exceptive syllogism, names the middle, minor and major terms, describes the four figures and how the second, third and fourth are brought back to the first, and gives the four productive moods of the first figure only, “the one made the standard of the sciences”. It then shows conjunctive syllogisms built from conditional propositions and the rules of the exceptive syllogism.

The sixth part treats the “five arts”, the kinds of syllogism by the quality of their premises: demonstration, with the kinds of certain premises (first principles, observations, experiential and intuitive premises, widely transmitted reports, and propositions that carry their proofs with them); dialectic; rhetoric; poetics; and sophistry. The book ends with a single sentence: “What can be relied on is demonstration, and nothing else.”

4A complete logic in miniature

What sets the Īsāghūjī apart from Porphyry’s Isagoge is its scope. Porphyry wrote an introduction to the five universals; al-Abharī covers, in a few pages, the ground of the whole Arabic “Organon”, which counted nine books: Porphyry’s introduction plus Aristotle’s eight logical works. The TDV İslâm Ansiklopedisi calls it a concise overview of the whole of classical logic.

Much is left out. There is no treatment of the ten categories, of induction or of analogy; there are no modal propositions, no mixed (modal) syllogisms and no proof by reductio, and the productive moods are given for the first figure only. Later commentators and teachers filled these gaps, and an Ottoman scholar, Dāwūd Qārṣī, even wrote a “New Īsāghūjī” (1162/1748–49), almost twice as long, that adds the moods of all four figures and other material from more advanced handbooks.

The book also says little about its sources. It does not name Ibn Sīnā, Porphyry or Aristotle, and the TDV article notes that it does not always follow Ibn Sīnā, for example in the order in which the five universals are listed.

5Style

The Īsāghūjī is extremely short: about 1,300 words, or roughly eight pages in Edwin Calverley’s English translation. Sarıoğlu calls it the shortest work of the Isagoge tradition and at the same time the most comprehensive in coverage, comparable to a glossary of logical terms.

Each topic is a definition followed by its divisions and one or two examples. The examples are deliberately ordinary and recur throughout: “Zayd is a writer”, “every human is an animal”, “if the sun has risen, it is day”, “a number is either even or odd”. There is almost no argument or discussion; reasons are given only where a rule needs one, as for why the figures are four or how conversion is proved.

This brevity is what made commentary necessary. The text can be learned by heart, but it cannot be understood without a teacher or a commentary, and the commentaries that began to appear in the eighth/fourteenth century, such as al-Kātī’s, became its usual companions. Commentators also corrected it: Shams al-Dīn al-Fanārī, for instance, criticised some of al-Abharī’s examples, such as the one for signification by implication.

6Why it became the first book

The TDV İslâm Ansiklopedisi states simply that the Īsāghūjī became the first logic textbook taught in the madrasas, and the commentaries, curricula and printings described in the following articles confirm this from Istanbul and Cairo to Delhi, Kazan and Madura. In Ottoman madrasas it was taught until the end of the empire, and at al-Azhar, according to the Egyptian scholar al-Ahwānī, until the 1950s.

The sources point to several reasons. It was short enough to be memorised, yet it touched every part of logic; in this way a beginner met all the basic terms once before going on to longer works such as al-Kātibī’s Shamsiyya. Its own preface presents it as what “anyone beginning any of the sciences” needs, not only future logicians. And the commentary tradition that grew around it, from al-Kātī and al-Fanārī to Zakariyyā al-Anṣārī, provided teachers with ready explanations at every level.

Its success can also be measured by its offshoots. In 941/1534 or thereabouts the Algerian scholar al-Akhḍarī turned it into a rajaz poem, al-Sullam al-munawraq, which became the first logic text in North Africa, Egypt and Indonesia; Ibrāhīm al-Shubrī also versified it. Together the Īsāghūjī and the Sullam made al-Abharī’s outline of logic the one most Muslim students met first.