The topic of indication and its divisions has no precedence in Stoic-Megarian logic and it is regarded as logical innovations of Ibn Sina. On the whole he can be conceived more as the founder of the topic of indications and not its expositor. Among the threefold literal connotation, indication per nexum has been more controversial of the rest. Ibn Sina's statements and above all in the works of his commentators and followers there has been much controversies and doubts, as regards the nature, condition of actualization or even the validity of this connotation. Doubt about non-independence of indication per nexum and its mixture of two corresponding connotation, doubt about rarity of connotation and interdiction of its applicability in the science because of non-infinity of its literal connotation have been among the most important of these doubts.This research, by emphasizing on the independence as well as literal mode of this connotation, tries to show that this connotation used in sciences, and regards the validity of this connotation as "mental necessity" and of the kind of "necessity between absolute".
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