AVICENNA (Ibn Sina) was and remains the preeminent Islamic philosopher. His works on science, metaphysics and medicine have had great influence on Islamic culture as well as on the West. Less known in the West are his logical works, as only his treatise on Porphyry's Isagoge was translated into Latin. A translation of Avicenna's "commentary" on Aristotle's On Interpretation, Al-'Ibara, is given here: the first in a Western language. Avicenna does not paraphrase the text but instead comments upon what the correct doctrines are. He offers original doctrines on such topics as predication, the logical square of opposition, and future contingents.

Avicenna uses and refers to these doctrines in his scientific works. This translation will contribute to a better understanding of Avicenna's overall philosophy.