Paul Vincent Spade

I am preparing an English translation of both the Tractatus longior and the Tractatus brevior of Walter Burley’s De puritate artis logicae for the “Yale Library of Medieval Philosophy.” My translation is based of course on the 1955 critical edition by Philotheus Boehner, the only reasonably reliable text available. Nevertheless, in preparing my translation, I have had several occasions to question or correct readings in Boehner’s edition. In some instances the corrections are merely obvious typographical errors, but in others there was something more substantive at stake. The text of the Tractatus brevior is particularly problematic in places, since there are fewer extant manuscripts on which to base an edition.

'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.

The manuscript Venice, Biblioteca Nazionale Marciana, Class XI n. 12, Zanetti Latini 301 (= 1576), contains on fols. 1r–24v a seemingly unique copy of a series of fifteen logical questions, ten on obligationes and the remaining five on insolubilia.1 The series on obligationes is untitled and unattributed in the manuscript, but the questions on insolubilia begin (fol. 18r11) “Incipiunt quaestiones super insolubilibus,” and are attributed at the end to a certain John of Wesel (fol. 24v41): “Ergo expletae sunt quaestiones insolubilium a Johanne de Vesalia Parixius2 disputatae. Deo gratias. Amen.”.

Apart from his Consolation of Philosophy, perhaps the most well known text of Boethius is his discussion of universals in the Second Commentary on Porphyry’s Isagoge.1 In that passage, he first reviews the arguments for and against the existence of universal entities, and then offers a theory he attributes to Alexander of Aphrodisias, a kind of theory called in recent times “moderate realism,” according to which there are no universal entities in the ontology of the world, but nevertheless there is an objective, non-arbitrary basis for the formation of our universal or general concepts about that world. At the very end of the passage, Boethius adds the intriguing comment that he has presented this view not necessarily because it is his own, but because it is the one that fits Aristotle’s..

The “dragon” that graces the cover of this volume has a story that goes with it. In the summer of 1980, I was on the teaching staff of the Summer Institute on Medieval Philosophy held at Cornell University under the direction of Norman Kretzmann and the auspices of the Council for Philosophical Studies and the National Endowment for the Humanities. While I was giving a series of lectures there (lectures that contribute to this volume, as it turns out), I went to my office one morning, and there under the door some anonymous wag from the Institute had slid the pen and ink drawing you see in the picture. It represents “Supposition” as a dragon, making a rude face at the viewer. The tail of the dragon is divided — not entirely accurately, as it turns out — into the various branches and subbranches of supposition. If the details are not altogether correct, the spirit is certainly understandable.