Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

Unusual Syllogisms: Avicenna and Najm al-Dīn al-Kātibī on per impossibile Syllogisms and Implication (luzūm)

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this article

+ Tax (if applicable)
Add to Favorites
You must be logged in to use this functionality

image of Oriens

In his proofs of e- and e-conversion in Logic for Shams al-Dīn, Najm al-Dīn al-Kātibī (d. 1276/7) accepts syllogisms that have redundant premises as theses. Similarities in Avicenna’s and Kātibī’s doctrines of the per impossibile syllogism suggest that Avicenna could have adopted such proofs and remained consistent with the principles of his syllogistic. However, analysis of their modal syllogistic and their ideas about the nature of implication (luzūm) reveals that Avicenna could not employ the type of per impossibile syllogism that Kātibī does and remain faithful to his modal theory, or to the Aristotelian vision of the theory of syllogistic as a theory of reasoning. In his commentary on Afḍal al-Dīn al-Khūnajī’s (d. 1248) Disclosure of Secrets Kātibī offers a second analysis of per impossibile syllogisms. Kātibī envisions a generic sense of logical necessitation that accommodates the sense in which an antecedent implies a consequent and premises imply a conclusion. This evidence may explain why Kātibī admitted redundantly concluding syllogisms as theses. If Avicenna was committed to a strict distinction between these senses, this may partially account for why Avicenna does not adopt Kātibī’s unusual syllogisms.

Affiliations: 1: Department of Classics and Ancient History, University of Manchester


Full text loading...


Data & Media loading...

Article metrics loading...



Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Subscribe to ToC alert
  • Get permissions
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
    Oriens — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation