This special issue grew out of a small conference The Known & the Unknown: Exploring Twelfth-Century Philosophy, which was funded by the Carlsberg Foundation, hosted by the Saxo Institute, and held at the University of Copenhagen in April 2018. Its central topic was the many, mostly unexplored, commentaries on Aristotle, Boethius, and Porphyry that constitute the key textual evidence for a fascinating phenomenon that, although it played a pivotal role in the philosophical revival of Western Europe, remains frustratingly underexplored to (...) this day: the logical schools of the twelfth century. The present introduction has two parts. In the first part, John Marenbon lays out the background to this special issue of Vivarium as a whole, explaining both what the philosophical project pursued by twelfth-century logicians was and how, and how far, the historical project of understanding it has progressed over the last two hundred years. In the second part, Heine Hansen briefly presents the issue and its contents. (shrink)

In this article, I shall consider medieval discussions of the principles of Aristotelian syllogistic which were called the dictum de omni et nullo and the expository syllogism. I am particularly interested in how theological questions contributed to the introduction of some influential new medieval ideas, such as the extensional sameness of the subject as the basis of predication, the interpretation of the expository syllogism from this point of view, and the explication of the logical subject of universal and particular syllogistic (...) premises with the phrase `Anything/something which is A. . .'. I end with some remarks about the increasing medieval awareness that these developments were beyond Aristotle's purview. (shrink)

Peter Abelard and William of Ockham represent the two main figures of the nominalism of the Middle Ages. Both share the fundamental thesis of that doctrine, according to which only individual entities exist. The repercussions of nominalism are quite evident in relation to the question of universals, which constitutes a subject that, until now, won the attention of the majority of contemporary studies on the two most important logicians of their time. Nevertheless the nominalism of each of these two protagonists (...) apparently diverges in a significant manner, especially in respect to the role exercised by the mind in the semantic process. Ockham seems to distance himself definitely from his predecessors, including Abelard, when he transfers grammar and semantic functions of conventional language to the level of mental language. In the present article, the chief intention is to expound the theory of sign and signification of each of the authors under consideration. The ultimate objective is to compare their respective semantic positions and indicate the principal points of agreement and disagreement, keeping in mind the hypothesis according to which these two medieval nominalists should have more theoretical elements in common than not. (shrink)