قاعده فرعيه در منطق جديد، گزارشي انتقادي از نزاع پنجاه ساله منطق قديم و جديد درباره پيش فرض وجودي در ايران

Principle of Existential Import: A Report on the Fifty Years Old Dispute between Ancient and Modern Logics on Existential Import in Iran

In a comparative study of ancient and modern logics, one of the most difficult issues is the existential import. Rejecting this assumption, modern logics has analyzed the quarter quantifieds in such a way that many of the propositions of ancient logics have lost their validity. In dealing with this issue, some have rejected the existential import of universals and some have blamed modern logic for its ignoring of this principle. With justifications or suggestions, a third group have tried to establish reconciliation between the two camps. The first group, the followers of modern logic, have nothing to say about the intuitive force of existential import and the second group have come empty-handed in dealing with the formal analysis and formulation of quarter quantifieds. The third group who have made valuable efforts in both fields constitute the focus of the present article in which it is demonstrated that all efforts of this third group have also doomed to failure. Each suggestion made by this group has failed to solve all the problems and created new issues instead. The article concludes that the old dispute between the two camps is still open because logicians in Iran have not been able to provide satisfactory analyses of the quarter quantifieds consistent with the existential import and the language of modern logic.