An important concept related to knowledge in al- Fārābī’s (872-950 AD)(and arabic) philosophy is certitude (al-yaqīn): “‘Certitude’ is identified as the cognitive state produced in the knower by her employment of demonstrative methods, in contrast to the inferior logical arts of dialectic, rhetoric, poetics, and sophistry, which produce cognitive states that approximate the certitude of demonstration in varying degrees. “Certitude” thus functions as a technical term in Arabic accounts of demonstration, to a large extent displacing the traditional identification of the end of demonstration as the production of “knowledge” or “science” (‘ilm, equivalent to the Greek epistēmē).”
Al-Fārābī writes about the notion of absolute certainty in his Book of Demonstration (Kitāb al-burhān) and the second is the Book on the Conditions of Certitude (Kitāb Šara’iṭ al-yaqīn). Here Al-Farabi names six, more and more restrictive criteria, the fulfillment of which lead to absolute certitude. These can be conceptualized as the differentia in the 10-fold Aristotelian categorization scheme [1.3.2].
The six criteria are:
- second order knowledge criteria: (C1) S believes that p; (C2) p is true; (C3) S knows that p is true;
- certitude criteria: (C4) it is impossible that p not be true; (C5) there is no time at which p can be false; (C6) conditions 1-5 hold essentially, not accidentally;
The process of getting to absolute certitude is shown in the UML Activity Diagram below, where S is the subject and p is the proposition:

By the end of this process the potentiality in Material Intellect becomes actualized in the Actual Intellect by grasping absolute certitude (see [32] also).
Sources
- All citations from: Deborah L. Black: “Knowledge (‘ilm) and Ceritude ( yaqīn ) in Al-Farabi’s Philosphy”, Arabic Sciences and Philosophy 16(01), March 2006
- López-Farjeat, Luis Xavier, “Al-Farabi’s Psychology and Epistemology”, The Stanford Encyclopedia of Philosophy (Summer 2018 Edition), Edward N. Zalta (ed.)
First published: 24/07/2019