Metaphysical Modality, Modality of Predicate and the Theory of

• Main Author: l nabavi
• Format: Article
• Language: fas
• Published: University of Isfahan 2010-05-01
• Series: Metaphysik
• Subjects: modality of predicate; metaphysical modality; theory of decisive necessity; equivalent - homogeneous model of possible worlds
• Online Access: http://uijs.ui.ac.ir/mph/browse.php?a_code=A-10-1-23&slc_lang=en&sid=1
• ISSN: 2008-8086; 2476-3276

Aristotle in the Organon (1949: 9,30 a ,15-19) explicitly states that in a categorical syllogism when the minor premise is absolute (without modality operator) and the major is necessary, the conclusion will be necessary too. This Aristotle's view has been the source of many conflicts and disputes in the history of logic. The famous logicians and historians of logic in the twentieth century as "Nicholas Rescher" and "Becker" believe that Aristotle's view is justifiable and defensible (at least compared to the first figure) only if, the modality of major premise is considered as the property of predicate (modality de re). Today, we know very well that the modality of predicate is closely linked to Metaphysical and philosophical Modality. “Shihab al-Din al- Suhrawardi” in the theory of "Decisive (Battateh) Necessity” by accepting this base, explicitly states that, in the beginning, the modality must be mentioned as a part of the predicate and then the modality of relation or copula is summarized and reduced to necessity. The modern formalization of the most important part of this theory is as follows: ("x) (àAx É à Bx) º ("x) □ (àAx É à Bx) This paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain).