This paper defends the thesis that the mediaeval genre of logical treatises De obligatiombus contained a theoretical account of counterfacutal reasoning, perhaps the first such account in the history of philosophy. This interpretation helps to explain some of the theoretical disputes in the obligationes literature in the first half of the fourteenth century. Section 1 is introductory. Section 2 presents Walter Burley's theory, while section 3 argues for the counterfactual interpretation of obligationes and section 4 discusses difficulties with Burley's theory. (...) Section 5 presents the textual basis for Richard Kilvington's theory, and section 6 outlines that theory. Section 7 discusses Roger Swyneshed's theory. Section 8 contains a summary and conclusion. (shrink)

The history of the mediaeval obligationes-literature has only recently begun to be studied. Two important treatises in this literature, one by Walter Burley and the other attributed to William of Sherwood, have been edited by Romuald Green in a forthcoming book. But there is considerable doubt concerning the authenticity of the text attributed to Sherwood. The correct attribution and dating of this treatise is crucial for our understanding of the history of this literature. In this paper, we argue that the (...) treatise is not as early as William of Sherwood, that on the contrary it dates no earlier than the very end of the thirteenth century, and that, although there is some contrary evidence, the treatise may be an early work by Walter Burley himself. (shrink)

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. (shrink)

'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. (shrink)

The Franciscan William of Ockham was an English medieval philosopher, theologian, and political theorist. Along with Thomas Aquinas and Duns Scotus, he is regarded as one of the three main figures in medieval philosophy after around 1150. Ockham is important not only in the history of philosophy and theology, but also in the development of early modern science and of modern notions of property rights and church-state relations. This volume offers a full discussion of all significant aspects of Ockham's thought: (...) logic, philosophy of language, metaphysics and natural philosophy, epistemology, ethics, action theory, political thought and theology. It is the first study of Ockham in any language to make full use of the new critical editions of his works, and to consider recent discoveries concerning his life, education, and influences. (shrink)

This is a supplement my original 2005 article "Insolubles" in the Stanford Encyclopedia of Philosophy.

What I want to talk about here is a puzzle for historians of philosophy who, like me, have spent a fair amount of time studying the history of mediaeval logic and semantic theory. I don’t know how to solve it, but in various forms it has come up repeatedly in my own work and in the work of colleagues I have talked with about it. I would like to share it with you now.

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.. (shrink)

Mediaeval logicians often wrote about changes between contradictory states, for example a switch’s changing from being on to not being on. One of the questions discussed in these writings was whether at the moment the change occurs the changing thing is in the earlier or the later state. The present paper investigates the general setting for that question, and discusses the answer given by Walter Burley, an important early-fourteenth century author whose theory was a standard one. Burley’s theory at first (...) seems arbitrary, and moreover committed to serious theoretical problems. The last part of the paper therefore considers what unspoken factors may have motivated Burley. Certain causal principles are suggested that would remove the apparent arbitrariness and avoid the theoretical problems with his theory, but only at the expense of revising it in a substantive way. (shrink)

A textual and philosophical study of the claim that according to ockham there is no synonymy or equivocation in mental language. It is argued that ockham is committed to both claims, Either explicitly or in virtue of other features of his doctrine. Nevertheless, Both claims lead to difficulties for ockham's theory.

This paper argues that Burley's theory of simple supposition is not as it has usually been presented. The prevailing view is that Burley and other authors agreed that simple supposition was in every case supposition for a universal, and that the disagreement over simple supposition between, say, Ockham and Burley was merely a disagreement over what a universal was (a piece of the ontology? a concept?), combined with a separate disagreement over what terms signify (the speaker's thoughts? the objects the (...) thoughts are about?).In fact, however, Burley explicitly allows that some instances of simple supposition are for an individual, and that in certain cases personal supposition and simple supposition coincide. The present paper explores Burley's theory on this topic, and proposes a way of thinking about the metaphysics and the semantics that makes sense of what he says. (shrink)

Mediaeval logicians often wrote about changes between contradictory states, for example a switch’s changing from being on to not being on. One of the questions discussed in these writings was whether at the moment the change occurs the changing thing is in the earlier or the later state. The present paper investigates the general setting for that question, and discusses the answer given by Walter Burley, an important early-fourteenth century author whose theory was a standard one. Burley’s theory at first (...) seems arbitrary, and moreover committed to serious theoretical problems. The last part of the paper therefore considers what unspoken factors may have motivated Burley. Certain causal principles are suggested that would remove the apparent arbitrariness and avoid the theoretical problems with his theory, but only at the expense of revising it in a substantive way. (shrink)

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.”. (shrink)

John Wyclif has been described as "ultrarealist" in his theory of universals. This paper attempts a preliminary assessment of that judgment and argues that, pending further study, we have no reason to accept it. It is certainly true that Wyclif is extremely vocal and insistent about his realism, but it is not obvious that the actual content of his view is especially extreme. The paper distinguishes two common medieval notions of a universal, the Aristotelian/Porphyrian one in terms of predication and (...) the Boethian one in terms of being metaphysically common to many. On neither approach does Wyclif 's theory of universals postulate new and non-standard entities besides those recognized by more usual versions of realism. Again pending further study, neither do Wyclif 's views appear to assign philosophically extreme or novel roles to the entities he does recognize as universal. On the contrary, by at least one measure, his theory of universals is less extreme than Walter Burley's, as Wyclif himself observes. For Wyclif, the universal is numerically identical with its singulars, but numerical identity is governed by something weaker than the Indiscernibility of identicals. (shrink)

1 There have been several editions of Fridugisus’ letter. I have consulted those in Jaques-Paul Migne, Patrologiae cursus completus … series latina, 221 vols., (Paris: J.-P. Migne, 1844–1864), vol. 105, cols. 751–756; Francesco Corvino, “Il ‘De nihilo et tenebris’ di Fredegiso di Tours,” Rivista critica di storia della filosofia (1956), pp. 273–286; and the most recent and authoritative edition, in Concettina Gennaro, Fridugiso di Tours e il “De substantia nihili et tenebrarum”: Edizione critica e studio introduttivo, (“Pubblicazioni dell’istituto universitario (...) di magistero di Catania,” serie filosofica — saggi e monografie, no. 46; Padua: Casa editrice Dott. Antonio Milani, 1963). Fridugisus’ letter survives in four manuscripts. Nevertheless the text is corrupt in places, and all editors have had to suggest emendations here and there. For my translation I have followed Gennaro’s edition, but not always her interpretation. There is another translation, by Hermigild Dressler, in John F. Wippel and Allan Wolter, eds., Medieval Philosophy from St. Augustine to Nicholas of Cusa, (New York: The Free Press, 1969), pp. 104–108. Note that references to the Psalms in this translation are given according to the numbering in the Revised Standard Edition. (shrink)