Volume One of Jewish Philosophy: Foundations and Extensions is divided thematically. 'Foundations of Jewish Philosophy' analyzes how Jewish philosophy is defined, the controversy over faith and reason, and how Sa' adiah Ga'on pioneered the medieval, and Moses Mendelssohn, the modern traditions of Jewish philosophy. 'Philosophy and Scripture' explores the relationship of the two major sources of religious thought, reason and revelation. 'Non-Philosophical Sources and Their Implications' discusses the existence of the boundaries of philosophical thought.