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 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 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 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)

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)

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 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.

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)

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)

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)

It is supposed to be common knowledge about the history of ideas that one of the few medieval philosophical contributions preserved in modern philosophical thought is the idea that mental phenomena are distinguished from physical phenomena by their intentionality, their directedness toward some object. As is usually the case with such commonplaces about the history of ideas, this claim is not quite true. Medieval philosophers routinely described ordinary physical phenomena, such as reflections in mirrors or sounds in the air, as (...) exhibiting intentionality, while they described what modern philosophers would take to be typically mental phenomena, such as sensation and imagination, as ordinary physical processes. Still, it is true that medieval philosophers would regard all acts of cognition as characterized by intentionality, on account of which all these acts are some sort of representations of their intended objects. This course is going to provide a broad survey of the conceptual relationships between intentionality, cognition and mental representation as conceived by some of the greatest medieval philosophers, including Aquinas, Scotus, Ockham and Buridan, and some of their lesser known contemporaries. The clarification of these conceptual connections sheds some light not only on the intriguing historical relationships between medieval and modern thought on these issues, but also on some fundamental questions in the philosophy of mind as it is conceived today. (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)

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.

“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)