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Reassessing Ninth Century Philosophy. A Synchronic Approach to the Logical Traditions

Periodic Reporting for period 4 - 9 SALT (Reassessing Ninth Century Philosophy. A Synchronic Approach to the Logical Traditions)

Reporting period: 2020-03-01 to 2021-02-28

This project aims at a better understanding of the philosophical richness of ninth century thought using the unprecedented method of a synchronic approach. The hypothesis guiding this synchronic approach is that studying together in parallel the four main philosophical traditions of the century - i.e. Latin, Greek, Syriac and Arabic - will bring results that the traditional enquiries limited to one tradition alone can never reach. The ninth century, a time of cultural renewal in the Carolingian, Byzantine and Abbasid empires, possesses the remarkable characteristic that the same texts, namely the writings of Aristotelian logic (including also Porphyry's Isagoge) were read and commented upon in Latin, Greek, Syriac and Arabic alike.
The project studies, in a precise historical context, fundamental questions related to the human capacity to rationalise, analyse and describe sensible reality, to understand the ontological structure of the world, and to define the types of entities which exist. It provides a unique opportunity to compare different traditions and highlight their common Aristotelian heritage, to stress the specificities of each tradition when tackling philosophical issues and to discover the doctrinal results triggered by their mutual interactions, be they constructive (scholarly exchanges) or polemic (religious controversies).
Logic is fundamental to philosophical enquiry, but it is also a fantastic tool to be used outside a strictly philosophical context. Logic is an extremely useful way to strengthen one’s own position, by establishing conclusions through rational deductions and by proposing syllogistic reasoning, but also to undermine the position of an adversary in an intellectual or religious controversy, by showing that his opinion implies contradictions or absurd consequences. Studying occurrences of such uses of logical tools is a precious mean for the historian to assess the place of rationality in public discourses.
The research done has made possible the elaboration of a new way of writing the history of Aristotelian logic during the ninth century, by considering not only purely philosophical works but also texts in which logic is applied to other problems.
These texts show the use of the art of correct reasoning, of proving a position, of showing the absurd consequences of the adversary’s opinion, of deductive and inductive reasoning and of using terms and concepts from Aristotelian logic to elaborate one’s own views on a question. These texts which apply logic are extremely rich mines of information. They are more personal than exegetical works, as they are in direct contact with the intellectual debates of the time, as logic is used to defend a position. They are also more original, as it is not the matter of reproducing traditional opinions, but to create new arguments. Being more personal and original, they show better what the logical culture of their authors has been than a reproduction of a well codified exegesis. By integrating them into the narrative, it was possible to write a far richer, more detailed and precise history of the reception and use of Aristotelian logic during the long ninth century, notably in Byzantium.

A great attention was given both to the conditions of the study of Aristotelian logic (manuscripts, teaching), its function and its appreciation (positive or critic) by ninth-century thinkers.The result is a social history of logic which includes analyses of the place logic in education, its use outside a philosophical context, and the modality of its textual transmission. The research done has underlined the central role of logical argumentation in several religious polemics of the ninth century as well as the stimulus for studying logic generated by these polemics.


The team has written 38 articles (the majority of them is already published, the rest is either under evaluation or in revision); several other texts are close to completion or in a first draft. Two books – an anthology of translations of Greek, Syriac and Arabic logical texts and a monograph offering the synthesis of the results as well as a new narrative of the reception and use of Aristotelian Logic during the long ninth century – will appear in 2022/3. We have edited one thematic issue and put together two thematic sections in leading journals of the fields. A dozen of conferences, colloquia, workshops and round tables were organised.
Results are of three kinds.

1. A new narrative of the history of logic during the ninth century. The traditional description includes only the analysis of the exegetical work done during the ninth century on Aristotelian logical texts. 9SALT takes into consideration a lot more material, by including in its study writings which are not primarily philosophical but in which logic is abundantly used (theological treatises or contributions to religious polemics for example). The consideration of this material allows a more detailed and precise picture, and a better evaluation of the role of logic, the level of scholarship and the logical culture of the main thinkers of the century. This aim is fulfilled through research articles and a monograph by the PI.

2. The use of the unprecedented synchronic approach allowed a deeper understanding of the positions held at the time, a clear identification of the a priori postulates (proper to each tradition) of the philosophical debates, and a critical evaluation of the arguments used. This was done through a comparison of the way in which philosophical problems are answered in the different traditions.

3. The making accessible of texts previously untranslated texts in English (or in other modern languages) in some cases, together with an edition of the text in original language. This is notably be done thanks to the publication of an anthology of logical texts in translation.
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