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.

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)

An argument with roots in ancient Greek philosophy claims that only humans are capable of a certain class of thought termed conceptual, as opposed to perceptual thought, which is common to humans, the higher animals, and some machines. We outline the most detailed modern version of this argument due to Mortimer Adler, who in the 1960s argued for the uniqueness of the human power of conceptual thought. He also admitted that if conceptual thought were ever manifested by machines, such an (...) achievement would contradict his conclusion. We revisit Adler’s criterion in the light of the past five decades of artificial-intelligence research, and refine it in view of the classical definitions of perceptual and conceptual thought. We then examine two well-publicized examples of creative works produced by AI systems and show that evidence for conceptual thought appears to be lacking in them. Although clearer evidence for conceptual thought on the part of AI systems may arise in the near future, especially if the global neuronal workspace theory of consciousness prevails over its rival, integrated information theory, the question of whether AI systems can engage in conceptual thought appears to be still open. (shrink)

This is a brief, accessible introduction to the thought of the philosopher John Buridan (ca. 1295-1361). Little is known about Buridan's life, most of which was spent studying and then teaching at the University of Paris. Buridan's works are mostly by-products of his teaching. They consist mainly of commentaries on Aristotle, covering the whole extent of Aristotelian philosophy, ranging from logic to metaphysics, to natural science, to ethics and politics. Gyula Klima argues that many of Buridan's academic concerns (...) are strikingly similar to those of modern philosophy and his work sometimes quite directly addresses modern philosophical questions. (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)

The final chapter provides a summary account of Buridan’s essentialist nominalism, showing how Buridan can successfully claim to be both a nominalist denying the existence of real shared essences and an essentialist endorsing the possibility of discovering truly essential attributes of things, which allows valid scientific generalizations. The concluding critical part of the chapter, however, points out a fundamental conflict between Buridan’s abstractionist cognitive psychology of absolute concepts and his logical semantics of the corresponding absolute terms that grounds his nominalist (...) essentialism. (shrink)

The second chapter spells out Buridan’s conception of logic as a practical science, teaching us, as logica docens, to heed the valid rules of reasoning embedded in our logical practice, logica utens. The chapter also deals with the particular difficulties of Buridan’s approach, considering his idea of the radical conventionality of written and spoken languages, consisting of token-symbols that owe their meaningfulness to the natural representational system of the human mind. This is the fundamental idea that naturally leads to the (...) nominalist conception of a mental language. On this conception, mental language itself is a compositional semantic system of naturally representative token-symbols, the singular mental acts of singular human minds. (shrink)

The first chapter presents a brief summary of the little we know about Buridan’s life, and the somewhat more we know about his immediate historical influence. But this brief survey of known facts only sets up the main argument of the chapter intending to show Buridan’s “modernity” in more than one sense of the word. Buridan is “modern” in the medieval sense, being “the great architect” of what would become in late-medieval philosophy the nominalist via moderna, but he is also (...) “modern” from our perspective, having many of the same concerns as contemporary analytic philosophers. Indeed, his philosophy can be the best key to understanding the major paradigm shifts between medieval and modern philosophy. (shrink)

The sixth chapter discusses the issue of how the reconstruction of the relevant parts of Buridan’s logic and medieval logic in general, using restricted variables, validates the attribution of existential import to affirmative propositions, in turn establishing the validity of all relations of the traditional Square of Opposition. The chapter also discusses how Buridan’s theory of natural supposition handles some objections to this conception concerning law-like statements, and, in general, how his theory of ampliation handles the issue of existential import (...) in intensional contexts. (shrink)

This chapter provides a comprehensive survey of Buridan’s conception of logical validity in a semantically closed token-based system, as he conceives of natural languages. The chapter argues first that Buridan has very good logical, as well as merely metaphysical, reasons to conceive of natural languages as compositional systems of significative token-symbols. Next, the chapter discusses the peculiar Buridanian conception truth and validity, according to which validity must not be based on truth, and truth need not always follow upon correspondence. These (...) results are presented as the consequences of Buridan’s pursuit of a consistently nominalist semantics for natural languages, able to handle the Liar Paradox and its kin involving reflective uses of language without the Tarskian distinction between object-language and meta-language, rejected for systematic reasons in the seventh chapter. (shrink)

The fifth chapter provides a detailed discussion of Buridan’s strategy of identifying the conceptual structures discussed in the chapter 4 by means of the various “syntactical clues” provided by spoken and written natural languages. The chapter compares the Buridanian strategy of “regimentation” with the modern strategy of formalization, and argues that for the purposes of a “natural logic” the former is not inferior to the latter. But in order to bridge the conceptual gap between the two approaches, the chapter also (...) discusses a simple extension of standard quantification theory that is capable of faithfully representing a large part of Buridan’s logic. Indeed, the chapter argues that the resulting formal system is in accord not only with Buridan’s logic, but with our natural language intuitions in general, providing more faithful representation of natural language reasoning than standard quantification theory. (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)

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)

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 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 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.

Common representational content allows the Buridanian classification of human concepts discussed in the fourth chapter, which provides the first thoroughgoing, systematic survey of Buridan’s conception of a mental language. The chapter discusses the divisions of concepts into syncategorematic and categorematic, simple and complex, absolute and connotative, and singular and common concepts. Besides presenting these classifications, the chapter provides a detailed discussion of the idea of conceptual complexity as semantic compositionality, its role in Buridan’s nominalist program of “ontological reduction,” and his (...) precarious positioning of his account of the distinction between the representational contents of universal and singular concepts “somewhere between” those of Ockham and Aquinas. The discussion relates the emerging issues to contemporary concerns in the philosophy of mind and language, such as the possibility of forming genuinely singular concepts and simple substantial concepts that would allow some terms of our language to function as rigid designators; the differences between consciousness and mental content; and the problem of universal representation without real universals. (shrink)

“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)

“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)

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.

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)

This volume features essays that explore the insights of the 14th-century Parisian nominalist philosopher, John Buridan. It serves as a companion to the Latin text edition and annotated English translation of his question-commentary on Aristotle's On the Soul. The contributors survey Buridan's work both in its own historical-theoretical context and in relation to contemporary issues. The essays come in three main sections, which correspond to the three books of Buridan's Questions. Coverage first deals with the classification of the science of (...) the soul within the system of Aristotelian sciences, and surveys the main issues within it. The next section examines the metaphysics of the soul. It considers Buridan's peculiar version of Aristotelian hylomorphism in dealing with the problem of what kind of entity the soul (in particular, the human soul) is, and what powers and actions it has, on the basis of which we can approach the question of its essence. The volume concludes with a look at Buridan's doctrine of the nature and functions of the human intellect. Coverage in this section includes the problem of self-knowledge in Buridan's theory, Buridan's answer to the traditional medieval problem concerning the primary object of the intellect, and his unique treatment of logical problems in psychological contexts. (shrink)

Contemporary "essentialism", if we want to provide a succinct, yet sufficiently rigorous characterization, may be summarized in the thesis that some common terms are rigid designators. [1] By the quotation marks I intend to indicate that I regard this as a somewhat improper (though, of course, permitted) usage of the term (after all, nomina significant ad placitum [2]). In contrast to this, essentialism, properly so-called, is the Aristotelian doctrine summarizable in the thesis--as we shall see, no less rigorous in its (...) own theoretical context--that things have essences. (shrink)

In this paper, I will primarily argue for the consistency of Aquinas’ conception, according to which the human soul, uniquely in God’s creation, is both the inherent, material, substantial form of the human body, and the subsistent immaterial substance underlying the immaterial operations of its immaterial, rational powers, namely, intellect and will. In this discussion, I will point out that typical challenges to Aquinas’ conception usually rely on semantic or ontological assumptions that can plausibly be denied in Aquinas’ own conceptual (...) framework. Since the issue of consistency merely assumes the less than self-evident claim of the immateriality of the human intellect, I will also provide a brief sketch of what I take to be Aquinas’ most promising proof of this claim. (shrink)

Saint Anselm’s proof for God’s existence in his Proslogion, as the label “ontological” retrospectively hung on it indicates, is usually treated as involving some sophisticated problem of, or a much less sophisticated tampering with, the concept of existence. In this paper I intend to approach Saint Anselm’s reasoning from a somewhat different angle.

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.

This paper argues that Aquinas's conception of the human soul and intellect offers a consistent alternative to the dilemma of materialism and post-Cartesian dualism. It also argues that in their own theoretical context, Aquinas' arguments for the materiality of the human soul and immateriality of the intellect provide a strong justification of his position. However, that theoretical context is rather "alien" to ours in contemporary philosophy. The conclusion of the paper will point in the direction of what can be done (...) to render Aquinas's position more palatable to contemporary philosophers. (shrink)

Robert Pasnau’s paper presents a strong thesis, which it does not manage to substantiate. The thesis in question is that the Aristotelian doctrine of the identity of the knower and the known, as interpreted by St. Thomas, cannot possibly be used to fend off skepticism.

Thomas of Sutton was one of the earliest, and by all measures one of the most astute defenders of St. Thomas Aquinas’ characteristic theological and philosophical doctrines. As usual with medieval thinkers, we have little information regarding Sutton’s life..

Lo studio intende mettere in evidenza l'ambiguità della nozione di unità, intesa come entità numerica, con la nozione di unità quale sinonimo di essere. Sul primo concetto verte la parte iniziale dello studio, alla quale segue l'esame del significato ontologico di «uno». Le considerazioni fatte guidano l'A. a valutare i rapporti di relazione fra le nozioni di essere e uno, e quelle di sostanzialità, identità e semplicità in Tommaso. La gerarchia ontologica che ha al vertice l'essere assoluto e l'assoluta unità (...) implica la paradossale impossibilità di «significare» e definire la divinità. (shrink)

This paper is not going to offer any criticism of the way Gaven Kerr treats Aquinas’ argument. Instead, it offers an alternative way of reconstructing Aquinas’ argument, intending to strengthen especially those controversial aspects of it that Kerr’s reconstruction left untreated or in relative obscurity. Accordingly, although the paper’s treatment will have to have some overlaps with Kerr’s, it will deal with issues essential to adequate replies to certain competent criticisms of his argument untreated by Kerr. For the sake of (...) the “formally inclined” reader, the paper’s treatment will also include an Appendix offering a formal reconstruction of both the main argument and its sub-arguments to demonstrate the formal rigor of Aquinas’ original. (shrink)

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.