The Middle Ages is often viewed as a period of low intellectual achievement. The name itself refers to the time between the high philosophical and literary accomplishments of the Greco-Roman world and the technological advances that were achieved and philosophical and theological alternatives that were formulated in the modern world that followed. However, having produced such great philosophers as Anselm, Peter Abelard, John Duns Scotus, William of Ockham, Peter Lombard, and the towering Thomas Aquinas, it hardly seems fair to label the medieval period as such. Examining the influence of ancient Greek philosophy as well as of the Arabian and Hebrew scholars who transmitted it, the Historical Dictionary of Medieval Philosophy and Theology presents the philosophy of the Christian West from the 9th to the early 17th century. This is accomplished through a chronology, an introduction, appendixes, a bibliography, and hundreds of cross-referenced dictionary entries on the philosophers, concepts, issues, institutions, and events, making this an important reference for the study of the progression of human thought.