Iranian Institute of Philosophy Sophia Perennis 2251-8932 11 1 2015 09 01 Abul-Futuḥ Ibn-al-Ṣalaḥ Al-Ḥamadāni’s Treatise on the Fourth Figure Abul-Futuḥ Ibn-al-Ṣalaḥ Al-Ḥamadāni’s Treatise on the Fourth Figure 77 118 32899 FA Asadollah Falahiy 0000-0002-1878-8866 Journal Article 2014 04 07 Abul-Futuh Aḥmad ibn-Muḥammad ibn-al-Ṣalāḥ Al-Ḥamadāni, a logician who lived one century after Avicenna, is the first Muslim who enumerated and proved the valid and invalid moods of the Fourth Figure in his treatise: ‘On the Fourth Figure, which is attributed to Galen.’ A facsimile of this has been published in 1965, and one year later was published in USA with a fairly unsophisticated edition of Nicholas Rescher. This paper is a new edition of the treatise with many corrections and contains some new information about the history of the subject. Abul-Futuh Aḥmad ibn-Muḥammad ibn-al-Ṣalāḥ Al-Ḥamadāni, a logician who lived one century after Avicenna, is the first Muslim who enumerated and proved the valid and invalid moods of the Fourth Figure in his treatise: ‘On the Fourth Figure, which is attributed to Galen.’ A facsimile of this has been published in 1965, and one year later was published in USA with a fairly unsophisticated edition of Nicholas Rescher. This paper is a new edition of the treatise with many corrections and contains some new information about the history of the subject. http://www.javidankherad.ir/article_32899_b55ff6b67aa843c4100437816f6ce41a.pdf