Most infonnallogic texts and articles assume a verbal account of reasoning which defines "argument" as a set of sentences. The present paper broadens this definition in order to account for "visual arguments" which are communicated with nonverbal visual images. Standard approaches to verbal arguments are extended in a way that allows them to explain and evaluate visual argumentation.

In this paper we define an augmentation mHC of the Heyting propositional calculus HC by a modal operator ?. This modalized Heyting calculus mHC is a weakening of the Proof-Intuitionistic Logic KM of Kuznetsov and Muravitsky. In Section 2 we present a short selection of attractive (algebraic, relational, topological and categorical) features of mHC. In Section 3 we establish some close connections between mHC and certain normal extension K4.Grz of the modal system K4. We define a translation of mHC into (...) K4.Grz and prove that this translation is exact, i. e. theorem-preserving and deducibility-invariant. We have established (however, in this note we do not present a proof of this) that the lattice of all extensions of mHC is isomorphic to the lattice of normal extensions of K4.Grz (a generalization of the Kuznetsov and Muravitsky theorem). (shrink)

In this paper, I explore what gives collective testimony its epistemic credentials, through a critical discussion of three competing accounts of the epistemology of collective testimony. According to the first view, collective testimony inherits its epistemic credentials from the beliefs the testimony expresses— where this can be seen either as the beliefs of all or some of the group’s members, or as the beliefs of group itself. The second view denies any necessary connection to belief, claiming instead that the epistemic (...) credentials of collective testimony derive from the reliability or truth-conduciveness of the statement that expresses the testimony. Finally, the third view claims that the epistemic credentials of collective testimony derive from the fact that it involves undertaking a collective commitment to trustworthiness, which makes the group susceptible to rebuke and blame if its testimony is not trustworthy. I argue that this last account holds the most promise for preserving what is distinctive about testimonial knowledge while still underwriting a robust epistemology of collective testimony. (shrink)

Over the past few decades, Indigenous communities have successfully campaigned for greater inclusion in decision-making processes that directly affect their lands and livelihoods. As a result, two important participatory rights for Indigenous peoples have now been widely recognized: the right to consultation and the right to free, prior and informed consent (FPIC). Although these participatory rights are meant to empower the speech of these communities—to give them a proper say in the decisions that most affect them—we argue that the way (...) these rights have been implemented and interpreted sometimes has the opposite effect, of denying them a say or ‘silencing’ them. In support of this conclusion we draw on feminist speech act theory to identify practices of locutionary, illocutionary, and perlocutionary group silencing that arise in the context of consultation with Indigenous communities. (shrink)

According to a dominant understanding, the illocutionary domain is a bifurcated one, an amalgam containing both communicative speech acts (such as requesting and promising) and ceremonial speech acts (such as saying ‘I do’ in a marriage ceremony and naming a ship). Bifurcating the domain in this manner is commonly taken to be a primary lesson of Austin’s “How To Do Things With Words’, alongside that of according communicative speech acts a far greater prominence in terms of our core understanding of (...) illocution. In contrast, we draw on the resources provided by Austin’s work to provide a more unified conception of the illocutionary domain, one in which differences between communicative and ceremonial acts are themselves understood to emerge from a broader understanding of the illocutionary character of speech. (shrink)

According Philip Pettit, suitably organised groups not only possess ‘minds of their own’ but can also ‘make up their minds’ and 'speak for themselves'--where these two capacities enable them to perform as conversable subjects or 'persons'. In this paper I critically examine Pettit's case for group personhood. My first step is to reconstruct his account, explaining first how he understands the two capacities he considers central to personhood – the capacity to ‘make up one’s mind’, and the capacity to ‘speak (...) for oneself’ – before showing how he thinks these can be manifested in groups. With Pettit’s account duly reconstructed, I then turn to criticism, arguing that Pettit’s construal of making up one’s mind does not do proper justice to our first-personal self-understanding, nor to our characteristic interpersonal forms of engagement. This leads me, finally, to consider an alternative construal of ‘making up one’s mind’ and ‘speaking for oneself’ that is associated with the work of Richard Moran and whichargue, could usefully be exteextended to groups. (shrink)

Sometimes an individual gets taken as speaking for a wider group without laying claim to any such authority – they are thrust unwillingly, and sometimes even unknowingly, into the role of that grou...

Ratio, Volume 34, Issue 4, Page 334-344, December 2021.

In the pioneering article and two papers, written jointly with McKinsey, Tarski developed the so-called algebraic and topological frameworks for the Intuitionistic Logic and the Lewis modal system. In this paper, we present an outline of modern systems with a topological tinge. We consider topological interpretation of basic systems GL and G of the provability logic in terms of the Cantor derivative and the Hausdorff residue.

Thomas Taylor’s interpretation of Plato’s works in 1804 was condemned as guilty by association immediately after its publication. Taylor’s 1804 and 1809 reviewer thus made a hasty generalisation in which the qualities of Neoplatonism, assumed to be negative, were transferred to Taylor’s own interpretation, which made use of Neoplatonist thinkers. For this reason, Taylor has typically been marginalised as an interpreter of Plato. This article does not deny the association between Taylor and Neoplatonism. Instead, it examines the historical and historiographical (...) reasons for the reviewer’s assumption that Neoplatonic readings of Plato are erroneous by definition. In particular, it argues that the reviewer relied on, and tacitly accepted, ethical and theological premises going back to the historiography of philosophy developed by Jacob Brucker in his Historia critica philosophiae . These premises were an integral part of Brucker’s Lutheran religiosity and thus theologically and ethically biased. If these premises are identified, articulated and discussed critically—which they have not been so far in connection with Taylor’s reception—it becomes less obvious that the reviewer was justified in his assumption that the Neoplatonic reading was erroneous by definition. This, in turn, leaves Taylor’s Plato interpretation in a more respectable position. (shrink)

A description of the free cyclic algebra over the variety of Solovay algebras, as well as over its pyramid locally finite subvarieties is given.

This article critically explores the history and nature of a hermeneutic assumption which frequently guided interpretations of Plotinus from the 18th century onwards, namely that Plotinus advanced a system of philosophy. It is argued that this assumption was introduced relatively late, in the 18th and 19th centuries, and that it was primarily made possible by Brucker’s methodology for the history of philosophy, dating from the 1740s, to which the concept of a ‘system of philosophy’ was essential. It is observed that (...) the concept is absent from Ficino’s commentary from the 15th century, and that it remained absent in interpretations produced between the 15th and 18th centuries. It is also argued that the assumption of a ‘system of philosophy’ in Plotinus is historically incorrect—we do not find this concept in Plotinus’ writings, and his own statements about method point in other directions. Eduard Zeller is typically regarded as the first to give a satisfying account of Plotinus’ philosophy as a whole. In this article, on the other hand, Zeller is seen as having finalised a tradition initiated in the 18th century. Very few Plotinus scholars have examined the interpretative development prior to Zeller. Schiavone and Bonetti , for instance, have given little attention to Brucker’s introduction of the concept of a ‘system of philosophy’. The present analysis, then, has value for an understanding of Plotinus’ Enneads. It also explains why “pre-Bruckerian” interpretations of Plotinus appear alien to the modern reader; the analysis may even serve to make some sense of the hermeneutics employed by Renaissance Platonists and commentators, who are often eclipsed from the tradition of Platonism. (shrink)

CONTEMPORARY TREATMENTS OF INFORMAL FALLACIES TAKE TWO WRONGS REASONING AS A FORM OF FALLACIOUS INFERENCE. I ARGUE THAT SUCH INFERENCES ARE OFTEN VALID AND THAT AN ADEQUATE TREATMENT OF TWO WRONGS ARGUMENTS MUST DISTINGUISH VALID AND INVALID ARGUMENTS, RATHER THAN REJECT THEM OUT OF HAND.

How we talk about relations has a great influence on how we think about relations. By saying that Spain defeated the Netherlands we obviously say something entirely different from saying that the Netherlands defeated Spain. This makes many of us think that in the underlying relation itself one of the relata comes first and the other comes second. However, there are good reasons to view the order as a representational artifact. In this paper I present a new logic that allows (...) us to think and talk about relations in a coordinate-free manner. The logic is minimalistic in the sense that it has no predicates except equality, but its expressive power is the same as that of first-order predicate logic. (shrink)

We present some results on algebraic and modal analysis of polynomial distortions of the standard provability predicate in Peano Arithmetic PA, and investigate three provability-like modal systems related to the Gödel–Löb modal system GL. We also present a short review of relational and topological semantics for these systems, and describe the dual category of algebraic models of our main modal system.

I explore the possibility and rationality of interpersonal mechanisms of doxastic self-control, that is, ways in which individuals can make use of other people in order to get themselves to stick to their beliefs. I look, in particular, at two ways in which people can make interpersonal epistemic commitments, and thereby willingly undertake accountability to others, in order to get themselves to maintain their beliefs in the face of anticipated “epistemic temptations”. The first way is through the avowal of belief, (...) and the second is through the establishment of collective belief. I argue that both of these forms of interpersonal epistemic commitment can function as effective tools for doxastic self-control, and, moreover, that the control they facilitate should not be dismissed as irrational from an epistemic perspective. (shrink)

Trans of Color inclusion is not simply a gesture of affectionate commitment to María Lugones's theory of impure communities. Rather, it is required for the enactment of her liberatory theory within and across communities of color. While María Lugones's historico-theoretical analysis of the colonial/modern gender system relies upon anthropological citations of Native gender and sexual diversity, she argues that we must bracket gender for the benefit of [cis]women of color feminisms. However, if this bracketing does not first carefully uncover cisgender (...) histories of violence, then this decolonial feminist praxis reinscribes the invisibility of transphobia, racism, and colonialism's violent intersections, performing another mode of erasure and silence on Trans, Two-Spirit, and Nonbinary Native, Black, and Latinx peoples. In placing Lugones's texts into conversation with the voices of Two-Spirit and Trans of Color theorists, I argue that the mutilation of trans flesh makes possible the integration of [cis]People of Color into the gender–sex binary even if as failures. More important, this essay offers the beginnings of a phenomenological account of Trans World-Traveling, where the unruliness of Two-Spirit and Trans of Color bodies cocoons decolonial worlds from within the spiraling folds of abject flesh—always already in infra-communication with ancestral pasts, presents, and futures. (shrink)

The Physics is a most remarkable work, and profoundly influenced Medieval Philosophers. Thomas Aquinas wrote a detailed, impressive commentary. This essay studies in particular the composition of the Physics as Thomas saw it, his thorough study of Aristotle’s way of arguing and the important distinction he made between disputative arguments, which are only partially true, and arguments which determine the truth. Aristotle frequently uses proofs which are wrong when one considers the proper nature of bodies, but possible considering their common (...) nature. Thomas accepts proofs in the field of physics but discards those related to a certain mathematization of nature. Aristotle holds the unlimited possibility of movements becoming faster or slower, but according to Aquinas he is considering things in general : when we consider specific bodies there is a fastest movement. Thomas speaks of a way of reading a text which is according the intention of Aristotle, and proposes an understanding of particular texts based on the general doctrine of the Stagirite. Sometimes he goes beyond the text, as when defending the unity of time as dependent on the unity of the First Mover. The essay shows that in the commentary a coherent philosophy of nature shaping up. In some places Aquinas brings in God’s causality: nature is nothing else but the plan of divine art, placed within things. The study of nature shows that there is a first principle of the whole nature which is above everything, sc. God who gives being to things. (shrink)

Die Quellen der Aristoteles-Rezeption bzw. der aristotelischen Logik im byzantinischen Mittelalter sind nur teilweise oder gering erforscht. Eine der wichtigen Autoritäten dieser Tradition stellt Leon Magentenos (12. Jh.?) dar. Magentenos war Metropolit von Mytilene sowie ein Gelehrter, der Kommentare zu allen sechs Traktaten des aristotelischen Organon (Categoriae, De Interpretatione, Analytica Priora, Analytica Posteriora, Topica, Sophistici Elenchi) verfasst hat. Hier wird die kritische Edition des Kommentars zum zweiten Buch der Ersten Analytik zusammen mit seiner Übersetzung ins Englische vorgelegt. Untersucht werden auch (...) die dem Kommentar angehängten syllogistischen Diagramme. Kommentare zu Analytica Priora II nach der Spätantike und vor Magentenos waren eher eine Rarität, daher ist sein Kommentar eine wichtige Quelle für alle Forscher, die sich mit der Geschichte der byzantinischen Logik und der aristotelischen Kommentierung befassen. (shrink)

A class of toposes is introduced and studied, suitable for semantical analysis of an extension of the Heyting predicate calculus admitting Gödel's provability interpretation.

A new logic is presented without predicates—except equality. Yet its expressive power is the same as that of predicate logic, and relations can faithfully be represented in it. In this logic we also develop an alternative for set theory. There is a need for such a new approach, since we do not live in a world of sets and predicates, but rather in a world of things with relations between them.

Cette contribution propose une étude, à la fois historique et critique, des controverses autour de l’interprétation empiriste ou friesienne de la Critique de la Raison Pure dans la période de 1830 à 1870. Il s’agit de l’idée que les connaissances a priori existent, certes, mais que leur découverte, ou la conscience que nous en avons, est a posteriori, et par conséquent de nature psychologico-empirique.

INTRODUCTION Philosophical theology is the systematic inquiry about God's existence and being. We find it in Aristotle's Metaphysics, in Cicero's De natura ...