Book excerpt: Mullā Ṣadrā Shirāzī emerges as an original philosopher who had a sure understanding of his Greek and Islamic predecessors. He is worthy of study by scholars concerned with the development of Islamic philosophy because of his attempt to reconcile various currents of Islamic philosophical thought, particularly the peripatetic tradition of Ibn ʿArabī. Modern existentialists will be interested in his basic concern with the reality of existence and the unreality of essences or general notions.