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 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)

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 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)

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)

“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 volume is about the most mind-boggling sacrament of the Christian faith, also referred to as the Sacrament of the Altar, the Eucharist: in its Roman Catholic interpretation, the conversion of the substance of the bread and wine into the body and blood of Christ for Holy Communion. The challenge of providing a rational interpretation of this doctrine of faith proved to be one of the most contentious issues in the Western history of ideas, apparently going against self-evident metaphysical principles (...) (requiring accidents existing without a substance, and a body in several places at the same time, etc.), and dividing schools of thought, indeed, eventually, warring religious factions. The volume addresses both the metaphysical, theoretical issues involved in this challenge and the historical, theological developments of how meeting this challenge played out first in the schools and even later in religious schisms, leading to the paradigmatic shift from medieval to modern forms of thought. The essays of the volume derive from the lectures of an eponymous international conference held in Budapest, Hungary, which was also the occasion of founding the Society for the History of European Ideas (SEHI); accordingly, the book is the first volume of the annual Proceedings of the SEHI. This book is aimed just as much at laymen and religious scholars seeking a better understanding of their faith as at anyone seeking this understanding with a non-religious attitude. (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 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)

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)

“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 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.

Is Aquinas a representationalist or a direct realist? Max Herrera’s (and, for that matter, Claude Panaccio’s) qualified answers to each alternative show that the real significance of the question is not that if we answer it, then we can finally learn under which classification Aquinas should fall, but rather that upon considering it we can learn something about the intricacies of the question itself. In these comments I will first argue that the Averroistic notion of “intentional transfer”, combined with the (...) Avicennean idea of the indifference of nature, yielding the Thomistic doctrine of the formal unity of the knower and the known renders the question moot with regard to Aquinas, indeed, with regard to the pre-modern epistemological tradition in general. These considerations will then lead to a number of further, both historical and philosophical questions, which I will offer in the end for further discussion. (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)

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)

To many contemporary philosophers, the phrase “essentialist nominalism” may appear to be an oxymoron. After all, essentialism is the doctrine that things come in natural kinds characterized by their essential properties, on account of some common nature or essence they share. But nominalism is precisely the denial of the existence, indeed, the very possibility of such shared essences. Nevertheless, despite the intuitions of such contemporary philosophers,2 John Buridan was not only a thoroughgoing nominalist, as is well-known, but also a staunch (...) defender of a strong essentialist doctrine against certain skeptics of his time. But then the question inevitably arises: could he consistently maintain such a doctrine? (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)

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.

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..

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)