University of Qom Journal of Philosophical Theological Research 1735-9791 9 4 2008 08 22 Ecthesis: An Account and Evaluation Ecthesis: An Account and Evaluation 103 119 251 10.22091/pfk.2008.251 FA Mehdi ‘Azimi 12321445356457568689 Journal Article 2015 08 16 Among the most useful methods in traditional logic is Ecthesis (i.e. proof from supposition), on whose whatness and structure Muslim logicians disagree. On one hand, Suhrawardi and Fakhr ar-Razi consider it as a type of syllogism in the third figure, whereas on the other hand, Nasir-ad-din Tusi does not count it among syllogisms at all. The author in this essay firstly presents an account of three logicians’ viewpoints and then evaluates Nasir-ad-din Tusi’s opinions. <br />  Among the most useful methods in traditional logic is Ecthesis (i.e. proof from supposition), on whose whatness and structure Muslim logicians disagree. On one hand, Suhrawardi and Fakhr ar-Razi consider it as a type of syllogism in the third figure, whereas on the other hand, Nasir-ad-din Tusi does not count it among syllogisms at all. The author in this essay firstly presents an account of three logicians’ viewpoints and then evaluates Nasir-ad-din Tusi’s opinions. <br />  https://pfk.qom.ac.ir/article_251_d4d7793d236152ef18565791efa0dfb0.pdf