Jean Buridan

Aquinas, Ockham, and Burdan all claim that a person can be numerically identical over time, despite changes in size, shape, and color. How can we reconcile this with the Indiscernibility of Identicals, the principle that numerical identity implies indiscernibility across time? Almost all contemporary metaphysicians regard the Indiscernibility of Identicals as axiomatic. But I will argue that Aquinas, Ockham, and Burdan would reject it, perhaps in favor of a principle restricted to indiscernibility at a time.

Many things can be other than they are. Many other things cannot. But what are statements like these about? One answer to this question is that we are speaking of possible worlds: if something can be other than it is, then it actually is that way in some possible world. If something cannot be otherwise, it is not otherwise in any world. This answer is presently dominant in analytical philosophy of language and logic. What are these worlds? David Lewis famously (...) claimed that every world exists, just like ours does: there is no difference between the other worlds and ours. In contrast, the medieval thinker John Buridan understands modal logic in terms of objects and causal powers in this world: if something can be other than it is, then there is a causal power that can make it that way. If it cannot, then no causal power—not even God—can alter it, at least without destroying its nature. As we’ll see, the Lewisian plurality is not possible on Buridan’s account; accordingly, a basic tenet of classical theism is untenable on Lewis’s metaphysics. In short, either the Lewisian plurality is incoherent, or a core monotheistic tenet is impossible. (shrink)

If an argument is valid, it is impossible for its premises to be true, and its conclusion false. But how should we understand these notions of truth and impossibility? Here, I present the answers given by John Buridan (ca. 1300-60), showing (i) how he understands truth in his anti-realist metaphysics, and (ii) how he understands modality in connection with causal powers. In short: if an argument exists and is valid, there does not exist a power capable of making the premises (...) true and, at the same time, making the conclusion false. (shrink)

What is an occurrent mental state? According to a common scholastic answer such a state is at least in part a quality of the mind. When I newly think about a machiatto, say, my mind acquires a new quality. However, according to a view discussed by John Buridan (who rejects it) and John of Mirecourt (who is condemned in 1347 for considering it “plausible”), an occurrent mental state is not even in part a quality. After sketching some of the history (...) of this position, I will present two common arguments against it—the argument from change and the argument from agency. I will then turn to Mirecourt’s own position on the matter. Mirecourt, I show, in fact offers us two different theories about occurrent mental states. The first, which I call the conservation theory, accepts that mental states are in part qualities. However, a mental state is a quality together with an action on the side of the mind, namely, its conservation of a quality within itself. The second position, which I will call the pure-action theory, holds that an occurrent mental state is not even in part a quality; instead, it is an action the mind performs which is neither the production nor the conservation of a quality within itself. Mirecourt characterizes such pure actions as “modes” of the mind, and it is this position which is condemned in 1347. In the final section, I turn to an objection that both Buridan and Mirecourt raise against the pure-action theory: if accidental states of the mind are mere modes of the mind, then why not suppose that all accidents are mere modes of the subjects which they qualify? (shrink)

It may come as a surprise to readers familiar with the life and work of the Arts Master that he discusses the Eucharist at all. As he likes to remind us, theological topics are generally out of his wheelhouse. Even so, in his Questions on the “Metaphysics” of Aristotle (QM) 4.6, Buridan takes the sacrament of the Eucharist as a key data point in his discussion of Aristotle’s Categories. In the Eucharist, the accidents of the bread and wine—their color, texture, (...) and so on—remain intact, but the underlying substance is transubstantiated into the body and blood of Christ. Accordingly, God can preserve accidents independent of their underlying substance. Therefore, for our part we can use accidental terms, like whiteness, without connoting any substances, like communion bread. Moreover, it follows that, contrary to Aristotle, substance and the accidental categories are not the most general genera. Instead, being (ens) is, as Buridan concludes. Here, I trace Buridan’s thought on the metaphysical and semantic matters of substance in light of the Eucharist. The Eucharist is for him not only a theological truth, but a metaphysical and semantic datum as well. I conclude by asking why Buridan did not take any and all questions about the Eucharist to be out of his ken. What does this tell us about his attitude toward theology? This paper also includes, as an appendix, the first ever English translation of the question under discussion (QM 4.6): “Does the term being (ens) signify substances and accidents by one single concept or notion?”. (shrink)

The paper delves into manuscript sources connected with various disputations held at Prague University from around 1390 to 1420 and singles out a set of hitherto unknown quaestiones dealing with the nature of the human intellect and its relation to the body. Prague disputations from around 1400 arguably offer a unique vantage point on late medieval anthropological issues, since they encompass an entanglement of numerous doctrinal influences from Buridanian De anima commentaries to John Wyclif’s theories. The paper delineates several conceptual (...) tensions regarding the nature of the intellect, e.g., between materialism (entailed by the emphasis on the intellect’s inherence in the body) and personal immortality. It presents several strategies Prague masters employed to overcome these tensions. For example, an anonymous participant of the 1409 quodlibet develops the Buridanian distinction between the rationally demonstrable materialist tendency and the indemonstrable “catholic truth” about the intellect both inhering in and separable from the body. On the other hand, Wyclif’s adherents (Jacob of Mies and another anonymous master) postulate an immortal spirit hypostatically united to each human being beside the human soul educed from the potency of the matter. Yet, the boundaries between the doctrinal standpoints in question seem permeable, whereby a rigid definition of antagonistic groups in late medieval Prague intellectual milieu (e.g., Buridanians vs Wycliffites) is rendered ineffective. (shrink)

Scholastic philosophers can be quite funny. What’s more, they have good reason to be: Aristotle himself lists ready wit (eutrapelia) among the virtues, as a mean between excessive humor and its defect. Here, I assess Scholastic discussions of humor in theory, before turning to examples of it in practice. The last and finest of these is a joke, hitherto unacknowledged, which Aquinas makes in his famous Five Ways. Along the way, we’ll see (i) that the history of philosophy is not (...) so hostile to humor as is commonly supposed; and (ii) that the competing theories of humor like the Incongruity Theory and the Release Theory are not altogether incompatible. We’ll also see at least one example of an apparent attempt by modern translators to excise humor from a medieval text. Our considerations will open a window into what oral discussion and debate at medieval universities was actually like, and how we should understand the relationship between the texts we have now and the exchanges that actually occurred then. (shrink)

Historians have claimed that the two closely related concepts of animism and natural teleology were both decisively rejected in the Scientific Revolution. They tout Robert Boyle as an early modern warden against pre-modern animism. Discussing Avicenna, Aquinas, and Buridan, as well as Renaissance psychology, I instead suggest that teleology went through a slow and uneven process of rationalization. As Neoplatonic theology gained influence over Aristotelian natural philosophy, the meaning of animism likewise grew obscure. Boyle, as some historians have shown, exemplifies (...) this uneven process. There is an unresolved tension between his religious convictions and the implicit animism of his empirical practice. (shrink)

Scholarship on the philosophy of the Late Middle Ages has tended to overlook certain subject matters, especially some pertaining to ethics and political philosophy. My object of study in this paper is one of these overlooked notions, the idea of craft (ars) as an intellectual virtue. While recent publications have focused on sapientia and scientia, this paper aims to rehabilitate ars as a virtue, in particular John Buridan’s understanding of craft as an intellectual virtue in his Quaestiones super decem libros (...) Ethicorum Aristotelis ad Nicomachum. My goal is to examine Buridan’s analysis of craft as expounded in this commentary. Once the Picardian master’s theses have been presented, and the objections he raises have been reviewed along with the solutions proposed to those objections, I briefly suggest why craft might have been overlooked as a virtue. (shrink)

What makes a valid argument valid? Generally speaking, in a valid argument, if the premisses are true, then the conclusion must necessarily also be true. But on its own, this doesn’t tell us all that much. What is truth? And what is necessity? In what follows, I consider answers to these questions proposed by the fourteenth century logician John Buridan († ca. 1358). My central claim is that Buridan’s logic is downstream from his metaphysics. Accordingly, I treat his metaphysical discussions (...) as the key to his logic. As has been often noted, Buridan’s metaphysics are radically anti-realist about universals, though I think the depth and scope of his anti-realism has at times been papered over. Buridan constructs his logic on an amazingly spartan ontology, and this accomplishment is overdue for reconsideration. To the foregoing questions: truth is a feature of propositions, and of propositions only—not of proposition-like states of affairs, or anything like that. It is a function of the reference or supposition (suppositio) of their terms, which depends on predication in a propositional context. And necessary truth is grounded in causation: a predication is necessary if it cannot be falsified by any power, natural or supernatural, without ii annihilating what its terms stand for. “Socrates is a human”, for instance, can only be falsified by annihilating Socrates, and so it is a necessary truth. -/- These considerations provide an ample theoretical basis for a thorough examination of Buridan’s modal logic. This is what the thesis culminates with. In the final chapter, I set forth some novel and surprising findings, chief of which is this: Buridan’s modal syntax and semantics are nothing like Kripke’s—and indeed are incompatible with them. This has significant implications not only for modal logic and metaphysics, but for how we think about medieval logic and philosophy more generally. -/- Throughout the thesis, I advocate a methodology of emphasising the differences, rather than the similarities, between past and present thought. Buridan is wildly unlike what we’re used to, and we should let him speak for himself. (shrink)

Raccolta di saggi sulla storia della filosofia rinascimentale e moderna.

Raccolta di saggi sulla storia della filosofia rinascimentale e moderna.

Discussions about singular cognition, and its linguistic counterpart, are by no means exclusive to contemporary philosophy. In fact, a strikingly similar discussion, to which several medieval texts bear witness, took place in the late Middle Ages. The aim of this article is to partly reconstruct this medieval discussion, as it took place in Parisian question-commentaries on Aristotle’s De anima, so as to show the progression from the rejection of singular intellection in Siger of Brabant to the descriptivist positions of John (...) Duns Scotus and John of Jandun, and finally to the singularism of John Buridan. All these authors accept some kind of intellectual access to individuals. Therefore, the conundrum is not whether we have some kind of intellectual knowledge of individuals, but rather whether we can know them singularly. This article begins by presenting the crucial obstacle to singular intellection in Siger. Thereafter, the author shows that Jandun and Scotus depart in fundamental ways from Siger’s account, but that for them the intellection of individuals is of a general character. Finally, she proposes that Buridan is a genuine singularist. (shrink)

Till just few decades ago, scholars used to use the label ‘Ockhamism’ to mark a turning-point in the history of mediaeval philosophy, above all in the history of natural philosophy. That turning-point was exemplified by the once so-called ‘Buridanian school’, today known simply as ‘Parisian school of natural philosophy’, whose leading representative was for sure John Buridan. But looking carefully at some crucial points of the Picard master’s idea of ‘nature’, concerning specifically the relationship between God and secondary causes on (...) one side, and the role played by free will, both the divine and the human one, on the other side, one will find out that Buridan’s ‘Ockhamism’ is at least questionable: Scotus’ modal logic is the conceptual framework, within which he redetermines the boundaries of natural laws, but the ‘pure ockhamist’ idea of the prevalence of the will on the intellect in God’s nature is the source of an image of the world in which voluntary behaviours and natural laws are intertwined. Therefore, Buridan’s natural philosophy results as a peculiar synthesis of two of the main divergent lines of thinking of late mediaeval philosophy. (shrink)

According to Nicole Oresme (c. 1320–1382), human beings, unlike all other animals, consist of two substances: a thinking substance and a sensing substance. This paper presents and explores the arguments Oresme uses to arrive at this position, which is unusual in medieval philosophical psychology and which at least superficially – though their methods are completely different – resembles what Descartes concluded about the nature of the human soul and body two and a half centuries later. The paper also considers some (...) moments of ambivalence in Oresme’s presentation, as well as unresolved difficulties, several of which have theological as well as philosophical implications. (shrink)

As we now know, most, if not all, philosophers in the High Middle Ages agreed that what we immediately perceive are external objects and that the immediate object of perception must not be some image present to the mind. Yet most — but not all — philosophers in the High Middle Ages also held, following Aristotle, that perception is a process wherein the percipient takes on the likeness of the external object. This likeness — called a species — is a (...) representation (of some sort) by means of which we immediately perceive external objects. But how can perception be at once direct — or immediate — and at the same time by way of representations? The usual answer here was that the species represents the external object to some percipient even though the species itself is not at all perceived: the species is that by which I perceive and not that which I perceive. John Buridan defends this traditional view — call it direct realism with representations. However, just a couple of decades before Buridan, one of the more important philosophers at Paris, Durand of St.-Pourçain, had already rejected direct realism with representation. Durand defends what I will call direct realism without representations. On his view, a species is not at all necessary during overtly direct forms of perception, neither as cause nor as representation. This paper has two parts. In the first part, I will discuss some of the more interesting arguments that Durand makes against direct realism with representations. In the second part, I will look at Buridan's defense of the view. -/- . (shrink)

The focus of the article is the self-predication principle, according to which the/a such-and-such is such-and-such. We consider contemporary approaches (Frege, Russell, Meinong) to the self-predication principle, as well as fourteenth-century approaches (Burley, Ockham, Buridan). In crucial ways, the Ockham-Buridan view prefigures Russell’s view, and Burley’s view shows a striking resemblance to Meinong’s view. In short the Russell-Ockham-Buridan view holds: no existence, no truth. The Burley-Meinong view holds, in short: intelligibility suffices for truth. Both views approach self-predication in a uniform (...) way. We were unable to find a medieval philosopher who, like Frege, approaches self-predication in a non-uniform way. We do not want to dispute that there are also considerable differences between the contemporary and the fourteenth-century approach to self-predication. Importantly, fourteenth-century accounts of self-predication rely strongly on the identity theory of predication, and this theory is not endorsed by contemporary philosophers of language. Nevertheless, some basic tenets seem to us to be clearly shared between fourteenth-century and contemporary thinkers. (shrink)

The moral of Buridan's Ass is that it can sometimes be rational to perform one action rather than another even though one lacks stronger reason to do so. Yet it is also commonly believed that it cannot ever be rational to believe one proposition rather than another if one lacks stronger reason to do so. This asymmetry has been taken to indicate a deep difference between epistemic and practical rationality. According to the view articulated here, the asymmetry should instead be (...) explained by the difference between rational intentions and rational actions. Thus, it turns out, Buridan's Ass-style cases do not indicate an asymmetry between epistemic and practical rationality as such. (shrink)

This paper tries to understand how three medieval philosophers (Roger Bacon, Albert the Great and John Buridan) developed the idea of a special logic for ethics, taking into account Aristotle's thesis according to which ethics does not need theoretical syllogisms and uses a special kind of scientific reasoning. If rhetoric is a good candidate, we find three different readings of this approach and then three different theories of ethical reasoning.

This publication offers the first critical edition of John Buridan’s second set of questions on Aristotle's “De generatione et corruptione”. The edition was made by Michiel Streijger, Paul Bakker and Hans Thijssen. First published as a printed book in 2010, the publication has been converted to open access with the CC BY-NC-ND license as of September 2023.

This paper argues in the first place that nominalists are right in insisting against ontological realists that semantic universality does not require commitment to universal entities. However, Ockham, in his zeal to get rid of Scotus’s universal entities, swept under the carpet the issue of universal representational content of genuinely universal symbols, conflating it with the mere indifference of the information content of non-distinctive singular representations. Buridan did come up with an abstractionist theory of the formation of genuinely universal representational (...) content to solve the resulting issues, however, the paper argues further, his solution is committed to attributing the sort of “aspectuality” to universal absolute concepts that his Ockhamist semantics denies to them. The conclusion of the paper suggests how Aquinas’s “moderate realism” can provide a consistent solution without the ontological extravaganza of ontological realists, without conflating the mere indifference of singular representation with genuine universality, and without having to deny aspectuality to our quidditative universal concepts formed by abstraction. (shrink)

The paradox of ’Buridan’s ass’ involves an animal facing two equally adequate and attractive alternatives, such as would happen were a hungry ass to confront two bales of hay that are equal in all respects relevant to the ass’s hunger. Of course, the ass will eat from one rather than the other, because the alternative is to starve. But why does this eating happen? What reason is operative, and what explanation can be given as to why the ass eats from, (...) say, the left bale rather than the right bale? Why doesn’t the ass remain caught between the options, forever indecisive and starving to death? Religious pluralists face a similar dilemma, a dilemma that I will argue is more difficult to address than the paradox just described. (shrink)

Est-il possible de parler de ce qui n’est pas ou d’y penser sans présupposer une forme d’être pour cela même que nous pensons ne pas exister? La vieille énigme parménidienne, qui hante toujours la philosophie contemporaine, est au cœur non seulement de la philosophie médiévale mais aussi des études médiévales, comme en témoigne le récent ouvrage d’Alain de Libera sur la référence vide. L’objet de cette étude est en comparaison beaucoup plus...

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Philosophy 42.2 (2004) 219-220 [Access article in PDF] Jack Zupko. John Buridan: Portrait of a Fourteenth-Century Arts Master. Notre Dame: University of Notre Dame Press, 2003. Pp. xix + 446. Cloth, $70.00. Paper, $40.00. What does the name "John Buridan" call to mind? For many, including medievalists, not much at all—at best, perhaps, a set of apparently unrelated ideas: nominalism; an impetus theory of (...) projectile motion; and a peculiar account of the will (although "Buridan's ass," the indecisive donkey caught between two equally appetizing bales of hay, is not found in Buridan's writing). In correcting this ignorance—an injustice to arguably the most famous and influential philosopher of the early-to-mid-fourteenth century—the temptation might have been to articulate Buridan's "positions" on "the big questions," allowing readers to fit Buridan into received categories. Thankfully, the present work, the first book-length study of Buridan in any language, resists this temptation. The John Buridan that emerges from Jack Zupko's skillful "exercise in philosophical portraiture" doesn't serve to simply fill gaps in our awareness of the historical record, but to enlighten and challenge our understanding of the practice of philosophy and the study of its history.Zupko emphasizes throughout that Buridan was a teacher, a master of arts in Paris. Buridan's pedagogical concerns help make sense of his central work in logic. As the basis for his arts lectures, Buridan chose Peter of Spain's Summulae Logicales, but in commenting on Peter, Buridan moves beyond creative exegisis to comprehensive renovation. Buridan (c. 1300-c. 1361) naturally wanted to accommodate terminist or via moderna supposition theory; but more importantly, he wanted a logic text that would set out a general plan of philosophical inquiry, "a compendium of methods, a 'how-to' book for the philosopher" (135). Buridan thus designed his own Summulae de Dialectica as a new authoritative logic text, and Zupko persuasively argues that its "nominalism" should be understood as less a set of doctrines in theoretical logic, than a program of logical practice, an education in logic as the ars artium, the universal intellectual tool.Zupko's portrait of "Buridan's vision of the philosophical enterprise" is thus appropriately divided into two parts. The first summarizes Buridan's method as described in the individual treatises of his Summulae. The second displays the method in practice, rehearsing and evaluating some of Buridan's arguments on various subjects. Many scholars will gravitate first to the latter part, where Zupko offers important interpretations and clarifications of Buridan's views. In these chapters, Zupko helps us to appreciate, among other things: how the problem of universals served to help Buridan define the scope of philosophy (ch. 10); the philosophical modesty of Buridan's account of the intellectual soul's presence in the body (ch. 11); the relationship between Buridan's epistemology and the skepticism of his Parisian contemporary Nicholas of Autrecourt (ch. 12); the sense in which Buridan is an "empiricist," viz an epistemic naturalist and reliabilist (ch. 13); how Buridan regarded moral psychology as applied physics, treating virtue as a kind of impetus (ch. 14); how Buridan's account of freedom can be regarded as a "perfection" of Thomistic intellectualism (ch. 15).Throughout these discussions, Zupko always keeps in sight his larger purpose of illustrating Buridan's conception of philosophical inquiry. Zupko makes much of the fact that [End Page 219] Buridan never wrote as a theologian, remaining his entire career in the arts faculty, where he wanted logic to organize secular inquiry. As Zupko notes, in this way Buridan's scholastic project seems to prefigure the "modern." But Buridan seems modern in another way as well. As Zupko points out in his "Introduction," though a cleric, Buridan never joined a religious order, so that his ideas developed independently of the Franciscan and Dominican traditions. He was, then, a teacher without a tradition—at least without deliberate allegiance to tradition, although he was in many ways the product of traditional scholastic intellectual discipline.Perhaps this... (shrink)

The aim of this paper is to offer a critical assessment of Buridan's proposed solution to the bridge-keeper paradox. First, I will outline his proposed solution to the paradox, and, second, carefully analyse each issue mentioned in the proposed solution. Finally, I will attempt to conclude that Burden has implicitly accepted a three-valued logic that does not allow him to conclude that Plato ought not do anything.

Gauthier and Hobbes reduce Prisoners Dilemmas to co-ordination problems (CPs). Many think rational, face-to-face agents can solve any CP by agreed fiat. But though an agent can rationally use a symmetry-breaking technique (ST) to decide between equal options, groups cannot unless their members' STs luckily converge. Failing this, the CP is escapable only by one agent's non-rational stubbornness, or by the group's "conquest" by an outside force. Implications: one's strategic rationality is group-relative; there are some optimums groups in principle cannot (...) rationally choose; thus justice cannot always be a rationally contracted optimum. Howard Sobel provides the point of departure. (shrink)