Proof-theory has traditionally been developed based on linguistic (symbolic) representations of logical proofs. Recently, however, logical reasoning based on diagrammatic or graphical representations has been investigated by logicians. Euler diagrams were introduced in the eighteenth century. But it is quite recent (more precisely, in the 1990s) that logicians started to study them from a formal logical viewpoint. We propose a novel approach to the formalization of Euler diagrammatic reasoning, in which diagrams are defined not in terms of regions as in (...) the standard approach, but in terms of topological relations between diagrammatic objects. We formalize the unification rule, which plays a central role in Euler diagrammatic reasoning, in a style of natural deduction. We prove the soundness and completeness theorems with respect to a formal set-theoretical semantics. We also investigate structure of diagrammatic proofs and prove a normal form theorem. (shrink)

We introduce a simple inference system based on two primitive relations between terms, namely, inclusion and exclusion relations. We present a normalization theorem, and then provide a characterization of the structure of normal proofs. Based on this, inferences in a syllogistic fragment of natural language are reconstructed within our system. We also show that our system can be embedded into a fragment of propositional minimal logic.

This paper explores the question of what makes diagrammatic representations effective for human logical reasoning, focusing on how Euler diagrams support syllogistic reasoning. It is widely held that diagrammatic representations aid intuitive understanding of logical reasoning. In the psychological literature, however, it is still controversial whether and how Euler diagrams can aid untrained people to successfully conduct logical reasoning such as set-theoretic and syllogistic reasoning. To challenge the negative view, we build on the findings of modern diagrammatic logic and introduce (...) an Euler-style diagrammatic representation system that is designed to avoid problems inherent to a traditional version of Euler diagrams. It is hypothesized that Euler diagrams are effective not only in interpreting sentential premises but also in reasoning about semantic structures implicit in given sentences. To test the hypothesis, we compared Euler diagrams with other types of diagrams having different syntactic or semantic properties. Experiment compared the difference in performance between syllogistic reasoning with Euler diagrams and Venn diagrams. Additional analysis examined the case of a linear variant of Euler diagrams, in which set-relationships are represented by one-dimensional lines. The experimental results provide evidence supporting our hypothesis. It is argued that the efficacy of diagrams in supporting syllogistic reasoning crucially depends on the way they represent the relational information contained in categorical sentences. (shrink)

There is a widely held view that visual representations (images) do not depict negation, for example, as expressed by the sentence, “the train is not coming.” The present study focuses on the real-world visual representations of photographs and comic (manga) illustrations and empirically challenges the question of whether humans and machines, that is, modern deep neural networks, can recognize visual representations as expressing negation. By collecting data on the captions humans gave to images and analyzing the occurrences of negation phrases, (...) we show some evidence that humans recognize certain images as expressing negation. Furthermore, based on this finding, we examined whether or not humans and machines can classify novel images as expressing negation. The humans were able to correctly classify images to some extent, as expected from the analysis of the image captions. On the other hand, the machine learning model of image processing was only able to perform this classification at about the chance level, not at the same level of performance as the human. Based on these results, we discuss what makes humans capable of recognizing negation in visual representations, highlighting the role of the background commonsense knowledge that humans can exploit. Comparing human and machine learning performances suggests new ways to understand human cognitive abilities and to build artificial intelligence systems with more human-like abilities to understand logical concepts. (shrink)

This paper provides a detailed comparison between discourse representation theory and dependent type semantics, two frameworks for discourse semantics. Although it is often stated that DRT and those frameworks based on dependent types are mutually exchangeable, we argue that they differ with respect to variable handling, more specifically, how substitution and other operations on variables are defined. This manifests itself in two recalcitrant problems posed for DRT; namely, the overwrite problem and the duplication problem. We will see that these problems (...) still pose a challenge for various extended compositional systems based on DRT, while they do not arise in a framework of DTS where substitution and other operations are defined in the standard type-theoretic manner without stipulating any additional constraints. We also compare the notions of contexts underlying these two kinds of frameworks, namely, contexts represented as assignment functions and contexts represented as proof terms, and see what different predictions they make for some linguistic examples. (shrink)

La figure du chat fait son apparition dans la littérature japonaise au ixe siècle, mais son image évoluera de manière inattendue à l’époque médiévale. Des témoignages littéraires du xie et du xiie siècle, tels que les Notes de chevet de Sei Shônagon et Le Dit du Genji de Murasaki Shikibu, montraient clairement l’intérêt porté aux chats par les dames de cour. Pourtant, à partir du xiiie siècle, le félidé fera au contraire l’objet d’une forme de « diabolisation », et c’est (...) cette dimension plus inquiétante du chat que nous aimerions évoquer ici, à travers trois exemples tirés du Kokon chomon-jû, vaste recueil de contes et légendes. Cette œuvre méconnue en Europe est attribuée à Tachibana no Narisue et achevée en 1254. The figure of the cat made its appearance in Japanese literature in the 9th century, but its image evolved unexpectedly in medieval times. Literary evidence from the 11th and 12th centuries, such as the Bedside Notes by Sei Shônagon and The Tale of Genji by Murasaki Shikibu clearly showed the interest of court women in cats. However, from the 13th century, the feline became the object of a form of “demonization”, and it is this more disturbing dimension of the cat that we would like to describe here, through three examples taken from Kokon chomon-Jû, a vast collection of tales and legends. This work, unknown in Europe, has been attributed to Tachibana no Narisue and was completed in 1254. (shrink)

In this paper, we argue that a distinction ought to be drawn between two ways in which a given world might be logically impossible. First, a world w might be impossible because the laws that hold at w are different from those that hold at some other world (say the actual world). Second, a world w might be impossible because the laws of logic that hold in some world (say the actual world) are violated at w. We develop a novel (...) way of modelling logical possibility that makes room for both kinds of logical impossibility. Doing so has interesting implications for the relationship between logical possibility and other kinds of possibility (for example, metaphysical possibility) and implications for the necessity or contingency of the laws of logic. (shrink)

Feinberg and Mallatt, in their presentation of neurobiological naturalism, have suggested that visual consciousness was acquired by early vertebrates and inherited by a wide range of descendants, and that its neural basis has shifted to nonhomologous nervous structures during evolution. However, their evolutionary scenario of visual consciousness relies on the assumption that visual consciousness is closely linked with survival, which is not commonly accepted in current consciousness research. We suggest an alternative idea that visual consciousness is linked to a specific (...) class of agency, consequently justifying their phylogenetic claim. We also examine the implication of their phylogenetic claim: visual consciousness is homologous across vertebrates, but its neural basis is not. This apparent incongruence illustrates a general phenomenon of homology, and that the resulting hierarchical view of visual consciousness and its neural basis can be straightforwardly accommodated by neurobiological naturalism. Throughout these discussions, we aim to address the potential theoretical issues in neurobiological naturalism and refine the picture illustrated by Feinberg and Mallatt regarding phylogenetic distribution and trajectories of visual consciousness. (shrink)

There was a time when 'logic' just meant classical logic. The climate is slowly changing and non-classical logic cannot be dismissed off-hand. However, a metatheory used to study the properties of non-classical logic is often classical. In this paper, we will argue that this practice of relying on classical metatheories is problematic. In particular, we will show that it is a bad practice because the metatheory that is used to study a non-classical logic often rules out the very logic it (...) is designed to study. (shrink)

It has been an open question whether or not we can define a belief revision operation that is distinct from simple belief expansion using paraconsistent logic. In this paper, we investigate the possibility of meeting the challenge of defining a belief revision operation using the resources made available by the study of dynamic epistemic logic in the presence of paraconsistent logic. We will show that it is possible to define dynamic operations of belief revision in a paraconsistent setting.

We propose a new information sharing system, named ``BisNet'', which automatically gathers information about the bookmarks stored in users' web browsers and helps the users exchange URIs of possibly interesting web pages with others who have similar interest with them. Being different from other typical agent services that gather and provide information according to pre-registered user profiles, BisNet is expected to share more relevant information because of its use of web browser bookmarks that are actively selected and ordered by many (...) humans. To enhance the relevance of information being shared, we developed a novel algorithm for directory evaluation. This algorithm only looks at the local referential structure between bookmark directories and URIs and calculates for each directory the ``order index'' that represents how well its content URIs are put in order with a focus on specific areas of interest. Then each directory receives new URIs from other related directories with large order indexes. The repetition of such URI exchanges makes the whole directory-URI networks dynamically form directory groups according to the commonness of the URIs they refer to. Our method is unique in that it pays no attention to the actual contents of web pages, and thus is much simpler and faster than other methods based on the result of content analysis. We carried out a field trial that involved 45 people who used a prototype version of BisNet clients. The result indicated that the relevance of shared URIs positively correlated with the ``order index'' of surrounding related directories, demonstrating the effectiveness of the method we proposed. (shrink)

One of the prime characteristics of the increasingly technological and interconnected world is the disappearance of analogue experience in all aspects of life. Due to technological invention, we are exposed to a variety of news and information, checking emails in private and business accounts for a significant amount of time each day. Our information-driven minds are constantly occupied by the desire to seek out more information. The ways we engage in music also have changed. We now download mp3 files and (...) listen to music on iPods. People are used to web-based, digitalized music listening.1 It is in this context that many people in the modern world are turning to indigenous forms of music that allow them to.. (shrink)

In this paper, we describe a collaborative information retrieval method among personal repositorie and an implementation of the method on a personal agent framework. We propose a framework for personal agents that aims to enable the sharing and exchange of information resources that are distributed unevenly among individuals. The kernel of a personal agent framework is an RDF(resource description framework)-based information repository for storing, retrieving and manipulating privately collected information, such as documents the user read and/or wrote, email he/she exchanged, (...) web pages he/she browsed, etc. The repository also collects annotations to information resources that describe relationships among information resources and records of interaction between the user and information resources. Since the information resources in a personal repository and their structure are personalized, information retrieval from other users' is an important application of the personal agent. A vector space model with a personalized concept-base is employed as an information retrieval mechanism in a personal repository. Since a personalized concept-base is constructed from information resources in a personal repository, it reflects its user's knowledge and interests. On the other hand, it leads to another problem while querying other users' personal repositories; that is, simply transferring query requests does not provide desirable results. To solve this problem, we propose a query equalization scheme based on a relevance feedback method for collaborative information retrieval between personalized concept-bases. In this paper, we describe an implementation of the collaborative information retrieval method and its user interface on the personal agent framework. (shrink)

This paper points out an error of Parigot’s proof of strong normalization of second order classical natural deduction by the CPS-translation, discusses erasing-continuation of the CPS-translation, and corrects that proof by using the notion of augmentations.

What does it mean for the laws of logic to fail? My task in this paper is to answer this question. I use the resources that Routley/Sylvan developed with his collaborators for the semantics of relevant logics to explain a world where the laws of logic fail. I claim that the non-normal worlds that Routley/Sylvan introduced are exactly such worlds. To disambiguate different kinds of impossible worlds, I call such worlds logically impossible worlds. At a logically impossible world, the laws (...) of logic fail. In this paper, I provide a definition of logically impossible worlds. I then show that there is nothing strange about admitting such worlds. (shrink)

Neurorights, as “new human rights,” have been increasingly recognized in the literature. In the Neurorights Initiative, these rights are supposed to be directed toward mental privacy, free will, pe...

CETTE THESE SE VEUT UNE CONTRIBUTION A LA COMPREHENSION DE LA DERNIERE PHILOSOPHIE DE MERLEAU-PONTY, EN PRENANT COMME FIL CONDUCTEUR LA NOTION D'INSTITUTION. NOUS ESSAYONS D'ABORD DE DELIMITER LE CHAMP D'INTERROGATION DE LA NOTION D'INSTITUTION, TELLE QU'ELLE EST PRESENTEE DANS SES DEUX PREMIERS OUVRAGES. DEUXIEMEMENT, LA DESCRIPTION DE QUATRE ORDRES DE L'INSTITUTION SYMBOLIQUE (ANIMALITE ET VIE; STYLE ARTISTIQUE; LANGUE ET IDEALITE; SYSTEME SOCIAL) QUE NOUS NOUS EFFORCONS DE RECONSTITUER A L'AIDE DES MANUSCRITS INEDITS CONDUIT A DEVOILER LES MOTIVATIONS DE LA (...) RADICALISATION DE LA QUESTION PHENOMENOLOGIQUE. ENFIN, NOTRE PROBLEMATIQUE SE PRESENTE DANS LE DERNIER OUVRAGE COMME UN PROJET DE L'INSTITUTION DE LA PHILOSOPHIE ELLE-MEME. CE PROJET A SA PORTEE HISTORIQUE, SE PROPOSANT DE METTRE EN EVIDENCE LES MOMENTS FECONDS DANS L'HISTOIRE DE LA PHILOSOPHIE, DE MANIERE A LEVER LES DIFFICULTES DE L'ONTOLOGIE ACTUELLE. (shrink)

In his book review of Graham Priest's The Fifth Corner of Four, Mark Siderits, while criticising Priest's philology, suggests that Priest's work is 'of considerable interest' for two reasons. First, 'when two independent traditions use similar methods to work on similar issues, it is always possible that one may have hit on approaches that the other missed'. Second, 'the decentering that can be induced by looking at another tradition may trigger fresh insights, even if those insights are not ones that (...) were actually developed by the tradition marked 'other''. The main task of this paper is to unpack Siderits' thought. By analysing some of Priest's work, I will suggest a decentering that must have taken place in China when Buddhism was 'exported to China in Buddhist shipping containers'. For anyone familiar with the forms of Buddhist philosophy developed in India, various forms of Chinese Buddhism can often look strange. Some ideas that were debated and defended by Indian Buddhists do not appear anywhere in Chinese Buddhism and some assumptions have been quietly added to Buddhism by Chinese Buddhists. By showing that Priest's work brings out the 'innovation' that Chinese Buddhists gave to Buddhism, I will suggest that it is this decentering that Siderits suggests Priest makes use of. (shrink)

A logic is said to be paraconsistent if it does not allow everything to follow from contradictory premises. There are several approaches to paraconsistency. This paper is concerned with several philosophical positions on paraconsistency. In particular, it concerns three ‘schools’ of paraconsistency: Australian, Belgian and Brazilian. The Belgian and Brazilian schools have raised some objections to the dialetheism of the Australian school. I argue that the Australian school of paraconsistency need not be closed down on the basis of the Belgian (...) and Brazilian schools’ objections. In the appendix of the paper, I also argue that the Brazilian school’s view of logic is not coherent. (shrink)

In the 1958-1959 Collège de France course, Merleau-Ponty expounds a detailed commentary on the last paragraphs of the Einleitung from Hegel’s Phenomenology of Spirit. We examine in what sense this course has developed the notions that he was in the process of defining, notions such as “chiasm,” “reversibility,” “depth,” and “flesh.” What seems crucial in this course is to clearly define good ambiguity as opposed to bad ambiguity, that is, to the simple mixture of finitude and universality, of interiority and (...) exteriority. It is a question then of revealing, even within Hegelian thought, the operation, although unstable, of good ambiguity and of instituting it beyond the distinction between anthropology and logic without a return to naturalism. It should first be noted that consciousness is for Hegel violence against itself, it gives itself its measure, such that the distinction between measuring and measured is internal to it. By insisting on this “reversibility” of the measuring and the measured, Merleau-Ponty comes to emphasize that the self-relation of consciousness is simultaneously its opening onto a transcendent – an opening whereby it learns something. This leads him to define “the new ontological milieu” which is the depth of the life of consciousness. It is within this depth that the interrogative experience winds on itself. Secondly, if there truly must be a moment where the Hegelian Zweideutigkeit becomes good ambiguity, it will not suffice to explore preobjective depth; it would still be necessary to discern “the hinge” which is “solid, unwavering” and which “remains irremediably hidden.” It is this unwavering hinge that supports phenomena and that, in simultaneously decentering and recentering the fields of appearances, opens a place where one can follow the genesis of sense. Finally, we note that this discovery of the new ontological milieu can be considered as the recovery of the notion of institution that Merleau-Ponty had proposed in 1954-1955: on the one hand, the notion of chiasm invites us to reveal the hinge which at once decenters and recenters the fields of appearances. This hinge is free from the alternative of nature and culture, of subjective and objective spirit; it is the rootedness of our interrogative experience in brute being, which is not object but starts an indefinite search of self. But, on the other hand, the notion of institution, which is essentially descriptive and factual, makes us better feel the weight of the instituted that is also irremediably hidden. It makes us feel the inertia of the instituting event, as well as its fecundity and its cumulativity. (shrink)

Logic in Buddhist Philosophy concerns the systematic study of anumāna (often translated as inference) as developed by Dignāga (480-540 c.e.) and Dharmakīti (600-660 c.e.). Buddhist logicians think of inference as an instrument of knowledge (pramāṇa) and, thus, logic is considered to constitute part of epistemology in the Buddhist tradition. According to the prevalent 20th and early 21st century ‘Western’ conception of logic, however, logical study is the formal study of arguments. If we understand the nature of logic to be formal, (...) it is difficult to see what bearing logic has on knowledge. In this paper, by weaving together the main threads of thought that are salient in Dignāga’s and Dharmakīti’s texts, I shall re-conceive the nature of logic in the context of epistemology and demarcate the logical part of epistemology which can be recognised as logic. I shall demonstrate that we can recognise the logical significance of inference as understood by Buddhist logicians despite the fact that its logical significance lies within the context of knowledge. (shrink)