جستجوی مقالات مرتبط با کلیدواژه « Traditional Logic » در نشریات گروه « فلسفه و کلام »

Though going back to Aristotle and porphyre Tyrien,the matter of the four relstions between two concepts, as a distinctive division, is one of the most important innovations in Arabic logic. This devision, for the first time, appeared in Farabi, Ghazali, Razi, and Khunaji in different forms. The devisions of the first three sufferred respectively from the fallacies of ‘non-coherency’, ‘non-exclusivity’ and ‘overlap of the sub-classes of the division’, so the later Arabic logicians didn’t accept them; thus Khunaji’s devision, laking all the fallecies, found its way to the pedagogical books and and established itself in Arabic logic up today. Although it has encountered important paradoxes from the very outset, it could resist all of them and reach its today firmed and established position in Arabic logic. In this paper, we explore the background of the four relations and determine each logician’s contribution in developing the subject.

Shams al-Din Samarqandi, a seventh Iranian logician, has proposed a new theory on conditional syllogism against Avicenna. Avicenna believed that conditional syllogism had only 19 valid moods; but Samarqandi, denying this similarity, validated only 7 moods. Samarqandi considered in his analysis only the quality conditions of the syllogism and did not pay attention to quantity conditions and in providing counterexamples for the invalid moods, he ignored their quantificational differences. If we consider just quality, as Samarqandi did, we’ll find a surprising similarity between his valid moods and the contemporary relevance logic, so that all Samarqandi’s valid moods are valid in relevance logic and vice versa. But if we look at the quantity of the propositions involved, we’ll encounter some difficulties, which are rooted in his interpretation of conditional quantifiers.

Two things which equal the same thing also equal one another. This well-known sentence had widely been accepted from the period of ancient Greeks and perhaps earlier as an evident axiom. By the introduction of Logic into the Islamic field، Ibn Sina and most of other Muslim logicians after him tried to affirm this chapter following the lead of Aristotelian syllogism or some other methods. However، it seems that their efforts haven’t been as fulfilled and have received criticism. Arguments for the above syllogism and other similar ones are also continued among the contemporaries. Nevertheless، it gives the impression that lack of enough attention to the contents of the premises of such syllogisms has led to the disappointment of any efforts in demonstrating them. Through the usage of the chapter of four-fold relations، in the analysis of these premises، the equality syllogism would easily be proved provided that the terms used in these syllogistics are universal. Furthermore، through the amalgamation of the chapters of syllogism and the four-fold relations a variety of other syllogisms corresponding to other relations other than equality would emerge all of which would be proved if we employ the previous method and within the traditional logic.