معارف منطقی

The hypothetical exceptive syllogism (qiyās al-istithnāʾ al-muttasil) is an important and widely used topic in Muslim logic, with roots dating back to ancient times and the Stoic logicians. While some logicians have regarded it as significant, its status has never been elevated to that of the categorical syllogism (qiyās al-iqtiṭānī). This article adopts a historical-analytical method to examine three main issues concerning this syllogism: its historical development, the nature and differences in Muslim logicians' conceptions of it, and its various forms. In the section on conceptual analysis, five distinct understandings of this syllogism (from al-Fārābī to Ījī Ṣafawī) are analyzed and evaluated, with al-Ghazālī's and Ījī Ṣafawī's definitions introduced as comprehensive and precise. Furthermore, the conditions for the syllogism's validity—including necessity (luzūmiyya), affirmation (ījāb), and the universality of the conditional premise—are examined in detail, and the viewpoints of various logicians on these matters are compared. Finally, the various forms of the connected exceptive syllogism from Ibn Sīnā's perspective and its inference based on categorical figures according to Ibn al-Nafīs's view are analyzed.