One of the key concepts in Medieval Jewish and Islamic Thought is the nature of the human soul and its corrolary immortality. The book discusses Gersonides' and Moshe Narboni's views in relations to their sources. It provides a critical analysis of Greek views of the noetic process and immortality. Since the philosophical tradition began with the writings of Plato and Aristotle and the commentators on Aristotle's work, Themistius and Alexander of Aphrodisias, their writings are dealt with in some detail. It also presents a detailed discussion on the writings of Alfarabi, Avicenna, Ibn Bajja, and Maimonides. Since Averroes is so important to both Gersonides and Narboni, a chapter examines his writings on the subject of intellection and immortality. The book then investigates the writings of Gersonides and Narboni and provides a comparative perspective on their views of immortality.