عنوان مقاله [English]
There are numorous logical works by Avicenna (Ibn Sina). With a critical scrutiny an evolution in these works can be recognized, both in the content and in the order of logical subjects. With the aid of those works with specified date, we can determine how the avicennan logic evolved. On this basis we find criteria to divide this evolution to three phases: the first period which is Aristotelian, the middle period which is a departure from Aristotle and the final period in which Avicenna presents his own account and segmentation of logic. Finally and on the basis of this division, one can find the date of those logical works with no specified date.