Draft:'usual-possibility' and 'narrow-possibility'


Avicenna has presented a variety of innovations and initiatives in completing and developing modal logic. His explanations of modal concepts are more expansive and accurate than his predecessors. Possibility is one of these modal concepts. In some of his books, such as al-Ibārah or al-Shifā, he refers to three meanings of possibility (usual possibility, narrow-possibility, future possibility), but in some of his books, such as Mantiq Al-Mushriqiyyïn or Al-Isharat wa l–tanbihat, he refers to four meanings (usual possibility, narrow-possibility, future-possibility, and narrowest-possibility).