Investigating the Problem of Universals in Ibn Sina's View and Its Interpretation by Khāja Tūsī with a Focus on Ishārāt wa Tanbīhāt

In the first pages of ‘theology’ in his Ishārāt, Avicenna claims that we may find out an abstract non-sensible thing through investigating the sensible things. By superimposing mixed quiddity over the non-conditioned quiddity, he argues that non-conditioned quiddity is free from the material accidents of mixed quiddities, hence non-sensible. This leads to misunderstanding that he regards the non-conditioned quiddity as existing out of the mind; thus, Khwāja Tūsī, unlike some of his books that regard general entities out of mind as impossible, in interpreting Avicenna’s statement says that non-conditioned quiddity, while non-sensible, is out of mind. This is in spite of the fact that Avicenna, based on his other books, regards general entities existing only in mind. It seems that in Ishārāt, Avicenna is seeking to prove that general entity in mind, i.e. non-conditioned quiddity in mind, is an abstract entity; thus, he prove an abstract being.