“The expression ‘free logic’ is an abbreviation for the phrase ‘free of existence assumptions with respect to its terms, general and singular’.”1 Classical quantification theory is not a free logic in this sense, as its standard formulations commonly assume that every singular term in every model is assigned a referent, an element of the universe of discourse. Indeed, since singular terms include not only singular constants, but also variables2, standard quantification theory may be regarded as involving even the assumption of (...) the existence of the values of its variables, in accordance with Quine’s famous dictum: “to be is to be the value of a variable”. (shrink)

This paper argues that three characteristic modern positions concerning intentionality – namely, (1) that intentionality is ‘the mark of the mental’; (2) that intentionality concerns a specific type of objects having intentional inexistence; and (3) that intentionality somehow defies logic – are just three ‘modern myths’ that medieval philosophers, from whom the modern notion supposedly originated, would definitely reject.

Summary: The aim of this paper is to explore the relationships between Buridan’s logic and the ontology of modes modi). Modes, not considered to be really distinct from absolute entities, could serve to reduce the ontological commitment of the theory of the categories, and thus they were to become ubiquitous in this role in late medieval and early modern philosophy. After a brief analysis of the most basic argument for the real distinction between entities of several categories (“the argument from (...) separability”), I point out that despite nominalist charges to the contrary, “older realists”—that is, authors working before and around Ockham’s time—were not committed to such real distinctions, and thus to an overpopulated ontology, by their.. (shrink)

This paper analyses the import of three claims extracted from Geach's works concerning theories of predication and the reference of common terms, the notions of being or existence, and the force/content distinction and theories of valid inference, respectively. The paper highlights the theoretical and historical errors involved in these claims as well as their enormous influence and inspiration in the field of the philosophical study of medieval logic and metaphysics.

Buridan's life, works, and influence -- Buridan's logic and the medieval logical tradition -- The primacy of mental language -- The various kinds of concepts and the idea of a mental language -- Natural language and the idea of a formal syntax in Buridan -- Existential import and the square of opposition -- Ontological commitment -- The properties of terms (proprietates terminorum) -- The semantics of propositions -- Logical validity in a token-based, semantically closed logic -- The possibility of scientific (...) knowledge -- Buridan's anti-skepticism -- Buridan's essentialist nominalism. (shrink)

This paper presents John Buridan’s nominalist ontology of habits, as the acquired qualities of innate powers aiding or hampering their operations, against the background of a more traditional interpretation of Aristotle’s doctrine to be found in Boethius, Albert the Great, Thomas Aquinas, and Cajetan. The paper argues that considerations of his late question commentary on Aristotle’s Nicomachean Ethics may have forced Buridan to rethink some of his earlier arguments for his parsimonious nominalist ontology of powers endorsed in such earlier works (...) as his Questions on Aristotle’s Categories and De anima. The lesson to be drawn from this investigation seems to be that upon working out the details of a nominalist programme in such fields as moral psychology and ethics, the requisite refinements sooner or later will involve such modifications of an originally “radical” programme that would bring it closer to what used to be the “mainstream” view. Even so, this much seems enough further down the line to change significantly how issues are framed relative to the “mainstream” view as well. (shrink)

In his admirably clear, beautifully argued study, Claude Panaccio has provided an able defense of Ockham’s position in response to an argument I presented against Ockham in a discussion with Peter King eight years ago at a meeting in Pittsburgh.1 But after eight years, and even after Claude’s book, I still stand by that argument. So, in these comments I will attempt to explain why I think Ockham may still not be off the hook.

In these comments I am going to argue that Yiwei Zheng's paper, by postulating an imaginary mental language in a proposed new interpretation of Ockham's conception of mental language, provides us with an imaginary solution to what turns out to be an imaginary problem. Having said this, however, I hasten to add that the paper has undeniable merits in pointing us in the right direction for revealing the imaginary character of the problem.

The third chapter discusses how Buridan’s conception of mental language provides the grounding for the objectivity and universality of logic despite the radical conventionality of written and spoken languages. Buridan’s conception, since it is based on the Aristotelian idea of the uniformity of natural human capacities in all individual humans, is nothing like modern psychologism, the kind heavily criticized by Frege. Indeed, Buridan’s mental language is not a “private language” criticized by Wittgenstein. On Buridan’s conception, the naturally representative units of (...) human mental language, namely, human concepts, are not inter-subjectively inaccessible private mental states; on the contrary, they are common to us all in our thinking. Of course, our concepts, being individual acts of individual minds are singular token-symbols, but they are common in their representational content: in what and how they represent for all humans. This is precisely the ground for their intersubjective accessibility as well as for the objectivity and universality of logic. (shrink)

This chapter provides a brief survey of Buridan’s reliabilist epistemology, contrasting it with skeptical challenges of his time, and comparing it with modern responses to similar skeptical challenges in modern philosophy, arguably stemming from the controversies of Buridan’s time. In particular, the chapter argues that the sort of “Demon-skepticism” modern readers are familiar with from Descartes was made conceptually possible precisely by the emergence of late-medieval nominalist semantics, and that the modern strategies responding to the skeptical challenge, exemplified by the (...) works of Thomas Reid and most recently John Greco, originate in the epistemic principles of Buridan. (shrink)

This collection of readings with extensive editorial commentary brings together key texts of the most influential philosophers of the medieval era to provide a comprehensive introduction for students of philosophy. Features the writings of Augustine, Thomas Aquinas, Boethius, John Duns Scotus and other leading medieval thinkers Features several new translations of key thinkers of the medieval era, including John Buridan and Averroes Readings are accompanied by expert commentary from the editors, who are leading scholars in the field.

We study the process of observation (measurement), within the framework of a “perspectival” (“relational,” “relative state”) version of the modal interpretation of quantum mechanics. We show that if we assume certain features of discreteness and determinism in the operation of the measuring device (which could be a part of the observer's nerve system), this gives rise to classical characteristics of the observed properties, in the first place to spatial localization. We investigate to what extent semi-classical behavior of the object system (...) itself (as opposed to the observational system) is needed for the emergence of classicality. Decoherence is an essential element in the mechanism of observation that we assume, but it turns out that in our approach no environment-induced decoherence on the level of the object system is required for the emergence of classical properties. (shrink)

This paper argues for two principal conclusions about natural language semantics based on John Buridan's considerations concerning the notion of formal consequence, that is, formally valid inference. (1) Natural languages are essentially semantically closed, yet they do not have to be on that account inconsistent. (2) Natural language semantics has to be token based, as a matter of principle. The paper investigates the Buridanian considerations leading to these conclusions, and considers some obviously emerging objections to the Buridanian approach.

Ramsey et al.'s article provides a more sensitive framework for comparative innovation than others' operationalisations have done. Nevertheless, a methodology has to be elaborated in order to determine to what degree a behaviour is novel. Psychological processes have to be considered when evaluating the value of reference groups and in order to figure out where to look for innovation.

This chapter focuses on how Aquinas’ solution of the problem of the persistence of eucharistic species and other scholastics’ reactions to it opened up certain conceptual possibilities in the Scholastic Aristotelian tradition that would not have been there without it, and which, therefore, were pointing the way toward later conceptual developments in the post-medieval and early modern philosophical traditions in logic, and metaphysics.

This paper primarily aims to provide a coherent interpretation of several, apparently conflicting claims made by Aquinas concerning the semantic function of the copula. The paper also argues that these claims can properly be understood only if they are interpreted as forming a coherent part of Aquinas' larger theory of the analogy of being. The Appendix sketches a model theoretical semantics for the reconstruction of Aquinas' relevant ideas, providing the technical means for setting apart the various senses of the verb (...) 'est' and its cognates distinguished by Aquinas. (shrink)

Under the traditional classification of medieval positions on the issue of universals, both Aquinas and Buridan would have to be deemed to be “conceptualists”: they both deny the existence of mind-independent, Platonic universals (against “realists”), and they both attribute universality primarily to the representative function of our universal concepts, and thus only secondarily to universal names of human languages (against “nominalists”). Yet, Aquinas is quite appropriately classified as a “moderate realist,” and Buridan as an “Ockhamist nominalist.” This paper will argue (...) that what justifies these more refined classifications is the two authors’ radically different conceptions of the representative function of our universal concepts. The paper will show how this difference results in their opposing judgments concerning the demonstrability of the thesis of the immateriality of the human intellect and will reply to Buridan’s main objection to Aquinas’s argument for this thesis, by pointing out the objection’s conflation of merely indifferent, non-distinctive singular representation with genuinely universal intellectual representation. In its conclusion, the paper will briefly gesture at an important contemporary implication of Aquinas’s thesis concerning a metaphysical limitation of artificial intelligence. (shrink)

This paper contrasts the Thomistic and Cartesian interpretations of what the substantial unity of the body and mind can consist in. A detailed discussion of the Thomistic account of the substantial unity of body and soul identifies especially those principles of the presupposed hylomorphist metaphysical background of this account that Descartes abandoned. After arguing for the consistency of the Thomistic view, briefly outlines how certain developments in late-medieval scholasticism prepared the way for the abandonment of precisely these principles. Finally, the (...) paper shows why from the perspective of the Thomistic principles identified in the first part, Descartes has to appear as someone paying mere lip-service to the thesis of the substantial unity of body and mind. (shrink)

This chapter compares the modern reliabilist strategies, including Buridan’s antiskepticism, considered in the previous chapter with a premodern form of antiskepticism, exemplified by Aquinas’s doctrine of “the formal unity of the knower and the known”, which, as the chapter argues, simply does not allow the emergence of “Demon-skepticism.” In fact, the chapter further argues that the emergence of “Demon-skepticism“ in its most extreme form, allowing an impossibility to appear as a possibility, indicates a serious flaw in the nominalist conception of (...) mental representation. Nevertheless, the chapter further argues that this flaw is easily masked by the apparent success of Buridan’s reliabilist strategy, not requiring the elimination of Demon-skepticism, but rather presenting reasonable ways for us to learn to live with it. (shrink)

This book provides the Latin text and its annotated English translation of the question-commentary of John Buridan (ca. 1300-1360) on Aristotle’s “On the Soul”. Buridan was the most influential Parisian nominalist philosopher of his time. His work speaks across centuries to our modern concerns in the philosophy of mind. This volume completes the project of a volume published earlier in the same series: “Questions on the Soul by John Buridan and Others”. An appealing book for scholars of Aristotle and those (...) who are in the field of Medieval philosophy. (shrink)

This chapter continues the discussion of the issues raised by the chapter 6, focusing on the issue of ontological commitment. The chapter argues that Buridan’s theory of ampliation, reconstructed in terms of quantification with restricted variables, provides a genuine third alternative to the opposing modern views of Quine and “the Meinongians.” Furthermore, the chapter argues that Buridan’s theory thus reconstructed says “all the right things” according to Quine in its object-language; however, it still seems to side with the Meinongians in (...) its meta-language. However, this is just a feature of the reconstruction: “the real Buridan” does not have this distinction, but works out his natural language semantics under conditions of what Tarski described as “semantic closure.”. (shrink)

It is a commonplace in the historiography of medieval philosophy that theology represents philosophy's culmination in the later Middle Ages, and specifically, that it is in the work of theologians and theologically-trained Arts Masters that we find philosophy in its purest and most advanced form. By comparison, the philosophy produced by thinkers who worked exclusively or primarily in the Faculty of Arts is seen as inferior -- by which is usually meant that it is shallow, unsophisticated, immature, and driven by (...) disparate curricular and pedagogical concerns rather than by the more single-minded commitment to rationally articulate that sacred doctrine which, as Aquinas says, "extends [by virtue of its oneness] to things which belong to different philosophical sciences.". (shrink)

Having seen the limitations of a reconstruction of Buridan’s semantics in terms of a modified quantification theory, this chapter begins engaging Buridan’s theory in its own terms, starting with a detailed discussion of the semantic properties of terms. The discussion moves from a brief discussion of Buridan’s distinction between immediate and ultimate signification, to Buridan’s theory of reference, namely, supposition, and oblique reference, namely, appellation. The chapter discusses suppositional descents as distinguishing quantifier-scopes, numerical quantification, and appellation in temporal and modal (...) contexts, as well as Buridan’s peculiar theory of appellatio rationis, the theory of oblique reference to concepts in intentional contexts. (shrink)

This chapter provides a systematic discussion of Buridan’s nominalist semantics of propositions and sentential nominalizations. The chapter argues that despite its incompleteness, Buridan’s theory is still “nominalism’s best shot” at a semantics of propositions without buying into a philosophically and theologically dubious ontology of dicta, enuntiabilia, complexe significabilia, real propositions, or states of affairs.

"What can a scholastic do in the 20 th century?" - asks Katalin Vidrányi in the title of her article written in 1970. [1] If her characteristically systematic and pithy analysis can be summarized in a single sentence, the author's answer is this: many things, but not too much.

“The problem of universals” in general is a historically variable bundle of several closely related, yet in different conceptual frameworks rather differently articulated metaphysical, logical, and epistemological questions, ultimately all connected to the issue of how universal cognition of singular things is possible. How do we know, for example, that the Pythagorean theorem holds universally, for all possible right triangles? Indeed, how can we have any awareness of a potential infinity of all possible right triangles, given that we could only (...) see a finite number of actual ones? How can we universally indicate all possible right triangles with the phrase ‘right triangle’? Is there something common to them all signified by this phrase? If so, what is it, and how is it related to the particular right triangles? The medieval problem of universals is a logical, and historical, continuation of the ancient problem generated by Plato's (428-348 B.C.) theory answering such a bundle of questions, namely, his theory of Ideas or Forms. (shrink)