Paul Thom’s book presents Kilwardby’s science of logic as a body of demonstrative knowledge about inferences and their validity, about the semantics of non-modal and modal propositions, and about the logic of genus and species. This science is thoroughly intensional. It grounds the logic of inference on that in virtue of which the inference holds. It bases the truth conditions of propositions on relations between conceptual entities. It explains the logic of genus and species through the notion of essence. Thom interprets this science as a formal logic of intensions with its own proof theory and semantics. This comprehensive reconstruction of Kilwardby’s logic shows the medieval master to be one of the most interesting logicians of the thirteenth century.

Cardinal and Archbishop of Canterbury Robert Kilwardby OP (c. 1215-1279) was a very important and influential thinker in his time, but he has not received the scholarly attention that he deserves. In this book we present the first study of all of his philosophical thinking from logic and grammar to metaphysics and ethics.

Early in the 1240s the University of Paris hired a recent graduate from Oxford, Roger Bacon by name, to teach the arts and introduce Aristotle to its curriculum. Along with eight sets of questions on Aristotle's natural works and the Metaphysics he claims to have authored another eight books before he returned to Oxford around 1247. Within the prodigious output of this period we find a treatise on logic titled Summulae dialectices, and it is this that is here annotated and presented in translation. The book is unique in several respects. First, there is the breadth of its sources. Not only do we find explicit reference to the usual authors such as Aristotle, Plato, Boethius, Porphyry, Cicero, and Priscian, we also find unexpected reference to Augustine, Bernardus Silvestris, Donatus, Terence, and Themistius, along with mention of the Muslim philosophers Algazel and Ibn Rushd. Second, it is clear that Bacon is drawing on or reacting to an extraordinarily wide variety of medieval sources: Garland the Computist, Hugh of St. Victor, Master Hugo, Hugutius of Pisa, Isidore of Seville, Nicholas of Damas, Nicholas of Paris, Richard of Cornwall, Robert Kilwardby, Robert of Lincoln, and Robert the Englishman. Third, it unexpectedly presents a full-blown treatment of Aristotle's theory of demonstration. And finally, Bacon reveals a highly unorthodox view of the signification of common terms. Bacon, here, takes his students and us deeper into medieval sources and controversy than any of his rivals do.

This wide-ranging collection of essays explores the nature of logic and the key issues and debates in the metaphysics of logic.

Peter Harrison takes what we think we know about science and religion, dismantles it, and puts it back together again in a provocative new way. It is a mistake to assume, as most do, that the activities and achievements that are usually labeled religious and scientific have been more or less enduring features of the cultural landscape of the West. Harrison, by setting out the history of science and religion to see when and where they come into being and to trace their mutations over timereveals how distinctively Western and modern they are. Only in the past few hundred years have religious beliefs and practices been bounded by a common notion and set apart from the secular. And the idea of the natural sciences as discrete activities conducted in isolation from religious and moral concerns is even more recent, dating from the nineteenth century. Putting the so-called opposition between religion and science into historical perspective, as Harrison does here for the first time, has profound implications for our understanding of the present and future relations between them. "

The first full-length study of Robert Kilwardby's commentary on Aristotle's Prior Analytics, based on a study of the medieval manuscripts.

John Buridan (ca. 1300-1362) has worked out perhaps the most comprehensive account of nominalism in the history of Western thought, the philosophical doctrine according to which the only universals in reality are "names": the common terms of our language and the common concepts of our minds. But these items are universal only in their signification; they are singular entities like any other in reality. This book examines what is most intriguing to contemporary readers in Buridan's medieval philosophical system: his nominalist account of the relationship between language, thought and reality. The main focus of the discussion is Buridan's deployment of the Ockhamist conception of a "mental language" for mapping the complex structures of written and spoken human languages onto a parsimoniously construed reality. Concerning these linguistic structures, this book carefully analyzes Buridan's conception of the radical conventionality of written and spoken languages, in contrast to the natural semantic features of concepts. The discussion pays special attention to Buridan's token-based semantics of terms and propositions, his conception of existential import, ontological commitment, truth, and logical validity. Finally, the book presents a detailed discussion of how these logical devices allow Buridan to maintain his nominalist position without giving up Aristotelian essentialism or yielding to skepticism, and pays special attention to contemporary concerns with these issues.