Shams al-Dīn Samarqandī’s Double Version of Exposition of Mixed Syllogisms Which are Composed of Ḥaqīqī and Khārijī Propositions

In this paper, we show that the extant manuscripts of Shams al-Dīn Samarqandī’s logical books Qisṭās al-afkār and Sharḥ al-Qisṭās exhibit a double version of exposition of mixed syllogisms which are composed of khārijī, ḥaqīqī and mental readings of quantified categorical propositions. This duble version presents different or even conflicting judgements on those mixed syllogisms. Because of the chronological precedence of one group of the manuscripts over the other, we call these two expositions "first version" and "second version," respectively. In addition, the manuscripts of both versions are divided into two groups. In one group, at the beginning of the section of propositions, when introducing the division of propositions into khārijī, ḥaqīqī and mental, a phrase is added to the manuscripts, which is only consistent with the contents of the second version. Since in the logical tradition in the Islamic world we have found the issue of mixed syllogisms composed of the three propositions only in these two works of Samarqandī, the importance of these two versions and of the added phrase is doubled and it must be examined whether the added phrase and the second version are from Samarqandī himself or from another scholar. In the present article, we will introduce the differences between the two versions and try to explain their relationship. In the end, we will critically edit the texts of these two versions in full.