Ibn Sina, Abu ‘Ali al-Husayn (980–1037)

Ibn Sina (Avicenna) is one of the foremost philosophers in the Medieval Hellenistic Islamic tradition that also includes al-Farabi and Ibn Rushd. His philosophical theory is a comprehensive, detailed and rationalistic account of the nature of God and Being, in which he finds a systematic place for the corporeal world, spirit, insight, and the varieties of logical thought including dialectic, rhetoric and poetry. Central to Ibn Sina’s philosophy is his concept of reality and reasoning. Reason, in his scheme, can allow progress through various levels of understanding and can finally lead to God, the ultimate truth. He stresses the importance of gaining knowledge, and develops a theory of knowledge based on four faculties: sense perception, retention, imagination and estimation. Imagination has the principal role in intellection, as it can compare and construct images which give it access to universals. Again the ultimate object of knowledge is God, the pure intellect. In metaphysics, Ibn Sina makes a distinction between essence and existence; essence considers only the nature of things, and should be considered apart from their mental and physical realization. This distinction applies to all things except God, whom Ibn Sina identifies as the first cause and therefore both essence and existence. He also argued that the soul is incorporeal and cannot be destroyed. The soul, in his view, is an agent with choice in this world between good and evil, which in turn leads to reward or punishment. Reference has sometimes been made to Ibn Sina’s supposed mysticism, but this would appear to be based on a misreading by Western philosophers of parts of his work. As one of the most important practitioners of philosophy, Ibn Sina exercised a strong influence over both other Islamic philosophers and medieval Europe. His work was one of the main targets of al-Ghazali’s attack on Hellenistic influences in Islam. In Latin translations, his works influenced many Christian philosophers, most notably Thomas Aquinas.