Logical Studies

Abstract In Islamic logic and philosophy usually is said, as a rule, that the attribution of logical secondary inteligibles is totally subjective. This paper shows that sometimes some Muslim thinkers, in practice, have violated this rule unintentionally, in the discussion of absolute non–existent paradox, for example. We will reinforce this violation and will present stronger arguments for the external and objective attribution of at least some logical secondary intelligibles, i.e. matters that are tied with intentionality and signification such as ‘cognition’, ‘information’, ‘describility’, ‘non-describility’, ‘knowability’. In this way the generality of this rule is violated.  

Abstract In the discussion of mingled modalities of the fist figure, Avicenna thought that the mode of conclusion doesn’t follow major premise just in two modes (the combination of proper minor with existential major and proper absolute minor premise with affirmative necessary) while according to the Khaje Toosi's thought, other modes, including attribute major (one of the general and specific conditional or general and specific conventional), don’t follow the mode of conclusion as well. Studying the works of the ancient logicians, we find out that the number of the modes comes up to 42. Identifying mode of conclusion, logicians are agreed on 31 modes, but disagreed on their rest 11, though none of them considered the conclusions of these 11 modes as followings of the major. The present thesis is studying the mentioned 31 modes, their standards/criterions and the logicians' reasons of the mode of conclusion. In addition, the issue of those 11 modes would be discussed later in an independent survey.
   

Abstract The main question of this paper is how one can devise a semantic theory in Mulla Sarad’s framework of thought. Indicating methodological points concerning the relation between semantics, metaphysics, epistemology, the article attempts to approach to Sarda’s semantic theory. Among the results of this article we can indicate to preference of logical language to natural language based on logical and demonstrative reason, determining word and sentence as the smallest meaningful units of language based on the theory of aspects, and non-interference of subject based on the emanation theory.

Abstract  Marga Reimer believes that ordinary speakers presuppose Meinongianism and their intuition about the meaningfulness of the sentences contained empty names is based on this fact. We will argue in this paper that her view is not strongly supported. More precisely, there is an alternative view that is incompatible with Reimer's view and as powerful as it in explaining speakers' intuitions. We will argue that there is no plausible reason for preferring Reimer’s view to this proposed alternative.

Abstract This article studies the stoic logic and the interpretation of which presented in the first half of twenty century. Since the encounters of the first researchers of this period to stoic logic is based on the modern logic presuppositions, we have called this approach classic and have attempted to examine the interpretations that this approach have presented of the connectives of the logic, i.e. disjunction, conjunction, conditional, and negation. In the lights of new works on stoic logic, the defects of the classic reading of these connectives will be shown. In the end of the paper we will explain that the classic understating of negation and conjunction connectives is right according to truth table, even though doesn’t convey stoic concepts completely. We will also show that the classic understanding of disjunctive and conditional connectives is wrong in some cases.            

Abstract Expressing the contradictory of atomic modal and universal compound modal, Khunaji utilizes two different methods to infer the contradictory of modal particular compound proposition. In one method, he accounts contradictory of modal particular proposition a disjunctive- predicated universal proposition and in the other method he accounts contradictory of this proposition a disjunctive proposition which the subject of one of the two sides is bounded by common predicate of disjunction particles. In this paper after a brief review of quality contradiction atomic modals and universal compound propositions in viewpoint of Khunaji, we will consider the quality contradiction particular compound modals in the viewpoint of this logician and we demonstrate that Khunaji is the inventor of the first method to infer the contradictory from this proposition and is the first logician discovered the disjunctive predicated proposition. We will also show  that Khunaji in the second method of inference was owed Kashshi and he was the second logician that utilizes this method.