From Peter's Blog ...
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For example: Google 'Avicennian logic' (including the quotes) and it returns 6,000 sites (the top one being the Wikipedia article on 'Avicennism', where the phrase originates). Yet I am sure there is no formal system of logic known to scholars as 'Avicennian logic'.
Peter,
In your blog you pick on "Avicennian logic" and suggest that it doesn't exist as a formal system of logic. Yet, the reference used in the entry on Avicennianism, which is
linkable through the entry, suggests that there is something that scholars would refer to as Avicennian logic, whether or not it actually fits the criteria of a "formal system of logic". Apologies for the long quote below from the Stanford Encyclopedia of Philosophy.
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The Arabic influence in logic is thinner than in other disciplines (apart from ethics), because only a few works of Arabic logic were translated into Latin. The most influential translations were the Isagoge part of Avicenna's summa The Healing (ash-Shifâ’) and al-GhazÄlī’s Intentions of the Philosophers, the first part of which is a reworking of Avicennian logic. Ramon Llull produced an Arabic compendium of al-GhazÄlÄ«'s text, which he himself translated into Latin (Lohr 1965). To these sources one may add al-FÄrÄbÄ«'s Enumeration of the Sciences, which transmitted much material on logical disciplines. Hermannus Alemannus's translation of Averroes' commentary on the Poetics was important because it remained the only source on Aristotelian poetics available in the Middle Ages and had a rich manuscript transmission (for its influence on Petrarch's negative judgement about Arabic poetry see Burnett 1997). Other translated texts remained largely uninfluential, such as William of Luna’s translations of five commentaries by Averroes on Aristotle’s logical works, or the translations made from Hebrew in the Renaissance. In sum, this means that the Latin West was not aware of the more innovative parts of Arabic logic, such as in syllogistics (Street 2005).
Of particular influence in scholastic philosophy was Avicenna's theory of the subject matter of logic, with its related doctrine of first and second intentions. Avicenna's basic claim is that logic deals with second-order concepts. This is discussed in the logic part of The Healing, but spelled out in technical vocabulary in the metaphysics part (Metaphysics I,2): "The subject matter of logic is the secondary intelligible concepts (al-ma'anî al-ma'qûla al-thâniyya, intentiones intellectae secundo), which depend on the primary intelligible concepts with respect to the manner by which one arrives through them at the unknown from the known". In this sentence, "concept" (ma'nâ) is rendered in Latin with the term intentio.
A brief note on this term is at place: In Arabic-Latin translation literature, intentio is very often used to render ma´nâ, with the consequence that the term intentio took on a similarly broad semantic range as its Arabic counterpart. In the writings of Avicenna, ma'nâ may mean "concept", but also "meaning" of a word, or something "intelligible" by the intellect, or "perceptible" by estimation but not by the external senses (on estimation see section 5.1). In Averroes' epistemology, the term ma'nâ has a specific meaning as the object of memory and a broader meaning as the abstracted content of sensory, imaginative or intelligible forms (Black 1996, 166).
In Avicenna's theory of logic, second intentions are defined as the properties of concepts which these concepts acquire when used in attaining knowledge, for example: being a subject or being a predicate, being a premise or being a syllogism. Avicenna thus confirms that logic has a proper subject matter, and hence becomes a full-fledged part of philosophy, and not only a tool for the philosophical disciplines (Sabra 1980, 752–753). Avicenna's definition of logic appears already in Dominicus Gundisalvi (De divisione philosophiae 150). Further Latin writers to adopt Avicenna's thesis that the subject matter of logic is second intentions are Roger Bacon and Thomas Aquinas, followed by many subsequent authors such as Pseudo-Robert Kilwardby, Radulphus Brito, Hervaeus Natalis, Peter Aureoli, Duns Scotus and William of Ockham (Knudsen 1982; Maierù 1987; Perler 1994).
It was a matter of dispute how first and second intentions differ, what they refer to and what their ontological status is, a dispute bordering on epistemology and the philosophy of mind. Important participants in this discussion are Roger Bacon, who defines intentions as intelligible species, that is, mental likenesses of things, and Hervaeus Natalis and Peter Aureoli, who (apart from disagreeing on many issues) both hold that intentions are neither identical with extramental things nor with qualities of the intellect; they have their own "intentional being" (esse intentionale), which is the result of a cognitive act (Perler 1994). This position was criticized both by nominalists and realists: William of Ockham objected against the reification of intentions and held that intentions are always natural signs in the mind; second intentions are natural signs which signify other natural signs (Summa logicae I.12); the realist author Walter Burley rejects the idea of a special being of intentions and argues that second intentions are part of extramental reality (Knudsen 1982). Logic as the science of second intentions continued to be a philosophical topic well into the sixteenth century, especially among Thomists and Scotist authors.
I have no doubt that this Jagged fellow has been doing some very sloppy and probably biased editing but this strikes me as an exceedingly sloppy example to be picking on. I hope the irony is also not lost on anyone here that no one is bothering to fact check the sloppiness of a WR contributer. It would also be nice to see some evidence of Jagged's misinformation actually making it into the rest of cyberspace. I don't see this, all I see is the mere fact that "Avicennian logic" turns up Google hits but then again it's used in the Stanford Encyclopedia so what does that prove? The real problem here is that the encyclopedia drives off people with actual expertise in subjects like this, and then someone arrives with good intentions and writes junk entries about subjects they have no business covering. The solution is of course for people who do have some knowledge in these areas to go about fixing the entries instead of wasting time discussing them. If Jagged has provided a very distorted picture of Avicenna's contributions to logic lets see it fixed.
Addendum -- Digging even further into the references on the entry produces an even more suggestive entry from the Stanford Encyclopedia regarding whether or not Avicennian logic can be described as a "system" or at least "school" of logic. Again this was
easily linkable through the entry.
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But the work on logic which was both technically advanced (and therefore unlike Ghazâlî's) and influential on later Arabic logicians (and therefore unlike Averroes') was done by Avicennan logicians who had begun to repair and reformulate Avicenna's work. Just as Avicenna had declared himself free to rework Aristotle as Intuition dictated, so too Avicenna's school regarded itself free to repair the Avicennan system as need arose, whether from internal inconsistencies, or from intellectual requirements extrinsic to the system. A major early representative of this trend is ‘Umar ibn Sahlân as-Sâwî (d. 1148) who began, in his Logical Insights for Nasîraddîn, to rework Avicenna's modal syllogistic.[13] It was to be his students and their students, however, who would go on to make the final changes to Avicennan logic that characterized the subject that came to be taught in the madrasa.
Sounds like a "system of logic" to this layman. I remain perplexed here.