Stephen Read

What binds the constituents of a state of affairs together and provides unity to the fact they constitute? I argue that the fact that they are related is basic and fundamental. This is the thesis of Factualism: the world is a world of facts. I draw three corollaries: first, that the Identity of truth is mistaken, in conflating what represents (the proposition) with what is represented (the fact). Secondly, a popular interpretation of Wittgenstein's Tractatus, due to Steinus, whereby false propositions are taken to picture non-existent state of affairs, cannot be right. For Wittgenstein, propositions had two poles, and a proposition and its negation picture the same fact. Finally, the metaphysics of modal realism must be wrong, for there are no non-actual states of affairs to constitute any world other than the actual world. (Published Online October 13 2005).

The recovery of Aristotle’s logic during the twelfth century was a great stimulus to medieval thinkers. Among their own theories developed to explain Aristotle’s theories of valid and invalid reasoning was a theory of consequence, of what arguments were valid, and why. By the fourteenth century, two main lines of thought had developed, one at Oxford, the other at Paris. Both schools distinguished formal from material consequence, but in very different ways. In Buridan and his followers in Paris, formal consequence was that preserved under uniform substitution. In Oxford, in contrast, formal consequence included analytic consequences such as ‘If it’s a man, then it’s an animal’. Aristotle’s notion of syllogistic consequence was subsumed under the treatment of formal consequence. Buridan developed a general theory embracing the assertoric syllogism, the modal syllogism and syllogisms with oblique terms. The result was a thoroughly systematic and extensive treatment of logical theory and logical consequence which repays investigation.

This volume, the first dedicated and comprehensive companion to medieval logic, covers both the Latin and the Arabic traditions, and shows that they were in fact sister traditions, which both arose against the background of a Hellenistic heritage and which influenced one another over the centuries. A series of chapters by both established and younger scholars covers the whole period including early and late developments, and offers new insights into this extremely rich period in the history of logic. The volume is divided into two parts, 'Periods and Traditions' and 'Themes', allowing readers to engage with the subject from both historical and more systematic perspectives. It will be a must-read for students and scholars of medieval philosophy, the history of logic, and the history of ideas.

Logical inferentialism claims that the meaning of the logical constants should be given, not model-theoretically, but by the rules of inference of a suitable calculus. It has been claimed that certain proof-theoretical systems, most particularly, labelled deductive systems for modal logic, are unsuitable, on the grounds that they are semantically polluted and suffer from an untoward intrusion of semantics into syntax. The charge is shown to be mistaken. It is argued on inferentialist grounds that labelled deductive systems are as syntactically pure as any formal system in which the rules define the meanings of the logical constants

This chapter focuses on alternative logics. It discusses a hierarchy of logical reform. It presents case studies that illustrate particular aspects of the logical revisionism discussed in the chapter. The first case study is of intuitionistic logic. The second case study turns to quantum logic, a system proposed on empirical grounds as a resolution of the antinomies of quantum mechanics. The third case study is concerned with systems of relevance logic, which have been the subject of an especially detailed reform program. Finally, the fourth case study is paraconsistent logic, perhaps the most controversial of serious proposals.

In this article, we discuss the notion of merely confused supposition as it arose in the medieval theory of suppositio personalis. The context of our analysis is our formalization of William of Ockham's theory of supposition sketched in Mind 86 (1977), 109-13. The present paper is, however, self-contained, although we assume a basic acquaintance with supposition theory. The detailed aims of the paper are: to look at the tasks that supposition theory took on itself and to use our formalization to relate them to more modern ideas; to explain the notion of merely confused supposition and to defend it against certain criticisms; and to discuss two issues closely related to the idea of merely confused supposition which we could not broach in a shorter article: the mode of supposition of terms in intensional contexts, and the possible existence of a fourth mode, often called suppositio copulatim

_ Source: _Page Count 21 Ian Rumfitt has recently drawn our attention to a couple of paradoxes of signification, claiming that although Thomas Bradwardine’s “multiple-meanings” account of truth and signification can solve the first of them, it cannot solve the second. The paradoxes of signification were in fact much discussed by Bradwardine’s successors in the fourteenth century. Bradwardine’s solution appears to turn on a distinction between the principal and the consequential signification of an utterance. However, although such a distinction played an important role in his successors’ theories, it is shown that Bradwardine’s account of signification does not admit any such distinction, no part being prior to the others. Accordingly his solution, unlike those of his successors, does not fall prey to Rumfitt’s paradoxes.

I. SUPPOSITION AND SIGNIFICATIONIn an insightful article on the medieval theory of supposition, Elizabeth Karger noted a remarkable development in the characterization of the material mode of supposition between William of Ockham and his contemporaries in the early fourteenth century and Paul of Venice and others at the turn of the fifteenth century.1. E. Karger, “La Supposition Materielle comme Supposition Significative: Paul de Venise, Paul de Pergula,” in A. Maierú, ed., English Logic in Italy in the 14th and 15th Centuries (Naples, 1982), pp. 331–41. For William, material supposition is explicitly ‘non-significative’, while for Paul, every mode of supposition is a kind of signification.2. Paul of Venice, Logica Magna (Tractatus de Suppositionibus), ed. and trans. A. Perreiah (St. Bonaventure, 1971), p. 4: “nam omnis suppositio est significatio.” In particular, we can set these definitions in opposition.

In his recent study, Concepts, Fodor identifies five nonnegotiable constraints on any theory of concepts. These theses were all shared by the standard medieval theories of concepts. However, those theories were cognitivist, in contrast with Fodor’s: concepts are definitions, a form of natural knowledge. The medieval theories were formed under two influences, from Aristotle by way of Boethius, and from Augustine. The tension between them resulted in the Ockhamist notion of a natural language, concepts as signs. Thus conventional signs, spoken and written, signify things in the world by the mediation of concepts which themselves form a language of thought, signifying those things naturally by their similarity. Indeed, later thinkers realised that everything signifies itself and what is like it naturally in a broad sense by means of the concept of its natural likeness

Stephen Read - Johannes Buridanus: Summulae de Practica Sophismatum - Journal of the History of Philosophy 45:1 Journal of the History of Philosophy 45.1 157-158 Muse Search Journals This Journal Contents Reviewed by Stephen Read University of St. Andrews Fabienne Pironet, editor. Johannes Buridanus: Summulae de Practica Sophismatum. Artistarium 10–9. Turnhout: Brepols 2004. Pp. xlix + 193. Paper, €40.00. John Buridan was an unusual figure in fourteenth-century logic and philosophy. Logic was at that time largely the preserve of the young, who would lecture on logic while studying in higher faculties such as theology, before moving on to lecture in their maturity on philosophy and theology. Two notable exceptions are the Englishman Walter Burley and the Frenchman from Picardy, John Buridan. Already active in the Arts Faculty at Paris in the late 1320s, Buridan was still there thirty years later. In the meantime, among other works on metaphysics, ethics, politics, and natural philosophy, he..