Epistemic Logic studies statements containing verbs such as 'know' and 'wish'. It is one of the most exciting areas in medieval philosophy. Neglected almost entirely after the end of the Middle Ages, it has been rediscovered by philosophers of the present century. This is the first comprehensive study of the subject. Ivan Boh explores the rules for entailment between epistemic statements, the search for the conditions of knowing contingent propositions, the problems of substitutivity in intentional contexts, the relationship between epistemic and modal logic, and the problems of composite and divided senses in authors ranging from Abelard to Frachantian.

Originally published in 1993, Modalities in Medieval Philosophy looks at the idea of modality as multiplicity of reference with respect to alternative domains. The book examines how this emerged in early medieval discussions and addresses how it was originally influenced by the theological conception of God acting by choice. After a discussion of ancient modal paradigms, the author traces the interplay of old and new modal views in medieval logic and semantics, philosophy and theology. A detailed account is given of late medieval discussions of the new modal logic, epistemic logic, and the logic norms. These theories show striking similarities to some basic tenets of contemporary approaches to modal matters. This work will be of considerable interest to historians of philosophy and ideas and philosophers of logic and metaphysics.

Central topics in medieval logic are here treated in a way that is congenial to the modern reader, without compromising historical reliability. The achievements of medieval logic are made available to a wider philosophical public then the medievalists themselves. The three genres of logica moderna arising in a later Middle Ages are covered: obligations, insolubles and consequences - the first time these have been treated in such a unified way. The articles on obligations look at the role of logical consistence in medieval disputation techniques. Those on insolubles concentrate on medieval solutions to the Liar Paradox. There is also a systematic account of how medieval authors described the logical content of an inference, and how they thought that the validity of an inference could be guaranteed.

Starting at the very beginning with Aristotle's founding contributions, logic has been graced by several periods in which the subject has flourished, attaining standards of rigour and conceptual sophistication underpinning a large and deserved reputation as a leading expression of human intellectual effort. It is widely recognized that the period from the mid-19th century until the three-quarter mark of the century just past marked one of these golden ages, a period of explosive creativity and transforming insights. It has been said that ignorance of our history is a kind of amnesia, concerning which it is wise to note that amnesia is an illness. It would be a matter for regret, if we lost contact with another of logic's golden ages, one that greatly exceeds in reach that enjoyed by mathematical symbolic logic. This is the period between the 11th and 16th centuries, loosely conceived of as the Middle Ages. The logic of this period does not have the expressive virtues afforded by the symbolic resources of uninterpreted calculi, but mediaeval logic rivals in range, originality and intellectual robustness a good deal of the modern record. The range of logic in this period is striking, extending from investigation of quantifiers and logic consequence to inquiries into logical truth; from theories of reference to accounts of identity; from work on the modalities to the stirrings of the logic of relations, from theories of meaning to analyses of the paradoxes, and more. While the scope of mediaeval logic is impressive, of greater importance is that nearly all of it can be read by the modern logician with at least some prospect of profit. The last thing that mediaeval logic is, is a museum piece. Mediaeval and Renaissance Logic is an indispensable research tool for anyone interested in the development of logic, including researchers, graduate and senior undergraduate students in logic, history of logic, mathematics, history of mathematics, computer science and AI, linguistics, cognitive science, argumentation theory, philosophy, and the history of ideas. - Provides detailed and comprehensive chapters covering the entire range of modal logic - Contains the latest scholarly discoveries and interpretative insights that answer many questions in the field of logic

In this book, the medieval development of Aristotle's theory of the modal syllogistic is studied for the first time. The book shows how this previously ignored part of medieval logic may give new insights into several areas of medieval philosophy.

A history of philosophy from 1100-1600 concentrating on the Aristotelian tradition in the Latin Christian West. "will long remain the major guide to later medieval philosophy and related topics. Most of the essays are exciting and challenging, some of them truly brilliant." --Speculum

’This sentence is false’ - is that true? The ’Liar paradox’ embodied in those words exerted a particular fascination on the logicians of the Western later Middle Ages, and, along with similar ’insoluble’ problems, forms the subject of the first group of articles in this volume. In the following parts Professor Spade turns to medieval semantic theory, views on the relationship between language and thought, and to a study of one particular genre of disputation, that known as ’obligationes’. The focus is on the Oxford scholastics of the first half of the 14th century, and it is the name of William of Ockham which dominates these pages - a thinker with whom Professor Spade finds himself in considerable philosophical sympathy, and whose work on logic and semantic theory has a depth and richness that have not always been sufficiently appreciated.