In this critical edition of Nicole Oresme's 14th-century treatise on atmospheric refraction, Oresme uses optics and infinitesimals to help solve this vexing problem of astronomy, proposing that light travels along a curve through the atmosphere, centuries before Hooke and Newton.

This book offers an entirely new perspective on the alleged incompatibility between Aristotelian philosophy and the mathematical methods and principles that form the basis of modern science. It surveys the tradition of the Oxford Calculators from its beginnings in the fourteenth century until Leibniz and the philosophy of the seventeenth century and explores how their various techniques of quantification expanded the conceptual and methodological limits of Aristotelianism.

This second edition concentrates on various philosophers and theologians from the medieval Arabian, Jewish, and Christian worlds. It principally centers on authors such as Abumashar, Saadiah Gaon and Alcuin from the eighth century and follows the intellectual developments of the three traditions up to the fifteenth-century Ibn Khaldun, Hasdai Crescas and Marsilio Ficino. The spiritual journeys presuppose earlier human sources, such as the philosophy of Plato, Aristotle, Plotinus, and Porphyry and various Stoic authors, the revealed teachings of the Jewish Law, the Koran and the Christian Bible. The Fathers of the Church, such as St. Augustine and Gregory the Great, provided examples of theology in their attempts to reconcile revealed truth and man’s philosophical knowledge and deserve attention as pre-medieval contributors to medieval intellectual life. Avicenna and Averroes, Maimonides and Gersonides, St. Thomas Aquinas and St. Bonaventure, stand out in the three traditions as special medieval contributors who deserve more attention. This second edition of Historical Dictionary of Medieval Philosophy and Theology contains a chronology, an introduction, appendixes, and an extensive bibliography. The dictionary section has over 300 cross-referenced entries on important persons, events, and concepts that shaped medieval philosophy and theology. This book is an excellent resource for students, researchers, and anyone wanting to know more about medieval philosophy and theology.

Natural philosophy encompassed all natural phenomena of the physical world. It sought to discover the physical causes of all natural effects and was little concerned with mathematics. By contrast, the exact mathematical sciences were narrowly confined to various computations that did not involve physical causes, functioning totally independently of natural philosophy. Although this began slowly to change in the late Middle Ages, a much more thoroughgoing union of natural philosophy and mathematics occurred in the seventeenth century and thereby made the Scientific Revolution possible. The title of Isaac Newton's great work, The Mathematical Principles of Natural Philosophy, perfectly reflects the new relationship. Natural philosophy became the 'Great Mother of the Sciences', which by the nineteenth century had nourished the manifold chemical, physical, and biological sciences to maturity, thus enabling them to leave the 'Great Mother' and emerge as the multiplicity of independent sciences we know today.

Superstitions are commonplace in the modern world. Mostly, however, they evoke innocuous images of people reading their horoscopes or avoiding black cats. Certain religious practices might also come to mind—praying to St. Christopher or lighting candles for the dead. Benign as they might seem today, such practices were not always perceived that way. In medieval Europe superstitions were considered serious offenses, violations of essential precepts of Christian doctrine or immutable natural laws. But how and why did this come to be? In Fearful Spirits, Reasoned Follies, Michael D. Bailey explores the thorny concept of superstition as it was understood and debated in the Middle Ages. Bailey begins by tracing Christian thinking about superstition from the patristic period through the early and high Middle Ages. He then turns to the later Middle Ages, a period that witnessed an outpouring of writings devoted to superstition—tracts and treatises with titles such as De superstitionibus and Contra vitia superstitionum. Most were written by theologians and other academics based in Europe’s universities and courts, men who were increasingly anxious about the proliferation of suspect beliefs and practices, from elite ritual magic to common healing charms, from astrological divination to the observance of signs and omens. As Bailey shows, however, authorities were far more sophisticated in their reasoning than one might suspect, using accusations of superstition in a calculated way to control the boundaries of legitimate religion and acceptable science. This in turn would lay the conceptual groundwork for future discussions of religion, science, and magic in the early modern world. Indeed, by revealing the extent to which early modern thinkers took up old questions about the operation of natural properties and forces using the vocabulary of science rather than of belief, Bailey exposes the powerful but in many ways false dichotomy between the "superstitious" Middle Ages and "rational" European modernity.

The Cambridge History of Medieval Philosophy comprises over fifty specially commissioned essays by experts on the philosophy of this period. Starting in the late eighth century, with the renewal of learning some centuries after the fall of the Roman Empire, a sequence of chapters takes the reader through developments in many and varied fields, including logic and language, natural philosophy, ethics, metaphysics, and theology. Close attention is paid to the context of medieval philosophy, with discussions of the rise of the universities and developments in the cultural and linguistic spheres. A striking feature is the continuous coverage of Islamic, Jewish, and Christian material. There are useful biographies of the philosophers, and a comprehensive bibliography. The volumes illuminate a rich and remarkable period in the history of philosophy and will be the authoritative source on medieval philosophy for the next generation of scholars and students alike.