I reconstruct J. H. Lambert’s views on how practical grounds relate to epistemic features, such as certainty. I argue, first, that Lambert’s account of moral certainty does not involve any distinctively practical influence on theoretical belief. However, it does present an interesting form of fallibilism about justification as well as a denial of a tight link between knowledge and action. Second, I argue that for Lambert, the persistence principle that underwrites induction is supported by practical reasons to believe; this (...) indicates that Lambert is a moderate pragmatist about reasons for theoretical belief. (shrink)

ABSTRACT The welcome expansion of kairos beyond its traditional locus in public debate to a broad range of discourse forms and persuasive actions has not been matched by a reevaluation of the temporal logic of kairos, which is still seen as located in teleologic time. This article suggests that Walter Benjamin’s understanding of time could refigure kairos as a nonteleological relationship among past, present, and future. Benjamin provides a theoretical rationale for kairotic action that is distributed in time and space (...) and accounts for kairos of objects, places, technologies, and works of art. These temporal affordances, usually developed separately in contemporary theory, are deeply connected in Benjamin’s writing; his understanding of time therefore integrates currently unconnected lines of research and supports a fluid but coherent understanding of kairotic agency. (shrink)

Turing's analysis of computation is a fundamental part of the background of cognitive science. In this paper it is argued that a re‐interpretation of Turing's work is required to underpin theorizing about cognitive architecture. It is claimed that the symbol systems view of the mind, which is the conventional way of understanding how Turing's work impacts on cognitive science, is deeply flawed. There is an alternative interpretation that is more faithful to Turing's original insights, avoids the criticisms made of the (...) symbol systems approach and is compatible with the growing interest in agent‐environment interaction. It is argued that this interpretation should form the basis for theories of cognitive architecture. (shrink)

The article will argue that Charles Sanders Peirce's concepts of the ‘Dynamics of Belief and Doubt’, the ‘Fixation of Belief’ as well as ‘habits of belief’ taken together comprise a theory of learning. The ‘dynamics of belief and doubt’ are Peirce's explanation for the process of changing from one belief to another. Teaching, then, would be an attempt to control that process. Teaching critical thinking represents an attempt to teach the learner to regulate and discipline his or her own (...) ‘settlement of belief’. The ‘settlement of belief’ takes four different forms based on doubt. Peirce's concept of the ‘habits of belief’ refers to the inner and outer constraints placed both on belief as such and belief as it becomes action. The article may be read as both an exegesis of learning and as a pedagogical guide for teaching critical thinking to college students. (shrink)

This conceptual paper explores the theoretical possibilities of posthumanism and presents ecologies of repair as a heuristic device to explore the association modes of different entities, which, when confronted with the effects of human-induced destructive events, seek to repair the damage and transform the conditions of coexistence of various life forms. The central idea is that severe socio-environmental crisis caused by an intensification of industrial activity are conducive to observing new sociomaterial configurations and affective dispositions that, through the reorganization of (...) practices of resistance, remediation, and mutual care, are oriented to generating reparative and/or transformative processes from damaged ecologies and communities. Crises constitute true ontological experimentation processes where the presence of other-than-human natures, and of artifacts or devices that participate in reparative actions, become visible. A post-human approach to nature allows us to use languages and methodologies that do not restrict the emergence of assemblages under the assumption of theira prioriontological separation, but rather examine their reparative potential based on the efficacy of situated relationships. Methodologically, transdisciplinarity is relevant, with ethnography and other engaged methods applied over units of observation and experience called socio-geo-ecologies. The relevant attributes of these socio-geo-ecologies, beyond the individual, community, or institutional aspects, are the specific geological characteristics that make possible an entanglement of interdependent relationships between human and non-human agents. The conceptual analysis is illustrated with empirical examples stemming from socio-geo-ecologies researched in Southern Chile. (shrink)

The paper begins as a response to Tom Rockmore's thesis that contemporary pragmatism is a healthy “confusion” of disparate views. While Rockmore sees the need of some of today's pragmatists to provide a motivation for what he calls “epistemic optimism,” I contend that the crucial question of pragmatism, the problem of pragmatism, is the ontological status of pragmatic meaning. Thus rather than a mere “epistemic optimism,” I call upon pragmatists to assert a fallible yet unabashedly metaphysical optimism. The argument supporting (...) this claim is made in the context of Peirce's “The Architecture of Theories.” In “The Architecture of Theories” Peirce opens the door to a pragmatic metaphysics while at the same time committing the error of subordinating truths and reality to “the long run of inquiry.” Rockmore suggest that the solution may lie in a return to Kant's notion of the “powers of the mind.” However, it is my contention that a solution to this problem cannot be found within Kant at all. I shall argue here that until contemporary pragmatism decisively extracts itself from the Kantian paradigm, the pragmatic philosophic value of pragmatic meaning will always be qualified, conditional and ontologically subordinated, having the same effect upon the standing of pragmatism as a philosophy as well. Moreover, I shall endeavor to show that when the Kantian paradigm is finally abandoned, pragmatism's classic difficulties with realism and what Peircc called “the long run” of scientific inquiry can also be resolved. Kantian “powers of the mind” and constructivist “epistemological optimism” would then be transformed into what I shall call unrestricted pragmatism. On the other hand if the Kantian impediment is not overcome, these difficulties will continue to form the basis of a more sceptical and traditionally restricted pragmatism, one which lacks the confidence desired by both Rockmore and myself. (shrink)

Rachel Wells turns to the examination of three recent artistic practices, which integrate facts in their work not as an antagonistic other but as a constitutive element to their efficacy and ethics. She argues, that in introducing news, factual actions, or objects with traces of factual events, Alfredo Jaar, Jeremy Deller and Martin Creed use facts in order to retract from the position of art as an expression of artistic freedom and subjectivity and thus as the opposite of fact. Instead, (...) she states that by introducing the factual the artists underline each in their own way the instability of given eptistemological and ethical frameworks. Far from being a mere relativist pose, Wells understands this denial of a stable subjectivist position as a reconfigured sense of “decision”—perhaps in the sense of Nancy’s articulation of a “decision of existence—that lets the factual take precedence over the control in and of the artwork as a heightened form of responsiveness and responsibility. Whereas Jaar uses the factual to engage overt political action, Deller presents facts that avoid taking an overtly critical perspective forcing the viewer to think about political events. Creed in contrast seeks for the interpretation of the past altogether, would avoid to take over the responsibility of taking a position. Whereas David Hume stated famously, that reasoning concerning matter of fact is founded in causality and Immanuel Kant concludes, that responsibility and freedom begins where causality ends, Wells understands the positions of Jaar, Deller and Creed as an attempt to reconcile the realm of the factual and the realm of the moral. Responsibility would then arise exactly out of the insight in the impossibility to ground moral stances in rationality and causality and in an attempt to use causality to demonstrate this impossibility. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 35.2 (2002) 120-137 [Access article in PDF] Discursive Mobility and Double Consciousness in S. Weir Mitchell and W.E.B. Du Bois 1 Susan Wells Here are two stories about double consciousness: they will become, eventually, stories about the public sphere: W. E. B. Du Bois formulating the theory of double consciousness, and S. Weir Mitchell presenting Mary Reynolds's case history, an instance of a mental disorder known (...) in the nineteenth century as double consciousness. I will begin with Du Bois's story, by far the most familiar to us: few texts are more central to contemporary rhetoric or cultural studies than the discussion of double consciousness in the opening pages of The Souls of Black Folk. 2 In the theory of double consciousness, Du Bois concentrated his contradictory experiences of scholarship, activism, social isolation, and active cosmopolitanism. Double consciousness was a methodological constraint that enabled Du Bois to build into the structure of The Souls of Black Folk a recognition that the complexity of African American life requires more than one perspective. And double consciousness was also a technique of writing, shaping the ironic and urgent voice of the book, by turns indignant and tender, eloquent and colloquial, a form of double address to both African American and Caucasian readers that allowed Du Bois to be two places at once. Double consciousness therefore controlled both the development and the presentation of The Souls of Black Folk, from the arc of its argument to its formal elements, includingDu Bois's famous use of chapter epigraphs to link canonic poetry with the melodies of the sorrow songs. Like the most relentlessly formal high modernist poem, the book continually enacts in its form not only its informing idea, but the circumstances of its composition and the constraints that shape its reading.The book's initial essay, "Of Our Spiritual Strivings," offers an analysis of double consciousness as it is shaped by three central categories of modernity: temporality, embodiment, and expertise. Double consciousness is located in time, in history; it is placed in a story of the epochal succession [End Page 120] of races, and in the specific history of slavery. Double consciousness emerges as strategically shaping African American responses to the problems of disenfranchisement, poverty, and the denial of civil rights after the suppression of Reconstruction. The historical sections of The Souls of Black Folk, therefore, do not simply rectify the facts, setting the record straight on Reconstruction or Afrocentric scholar and theorist Alexander Crumell. These local arguments all motivate an understanding of consciousness as temporally constituted, so that the work of previous generations can be effective only when it is appropriated in the present. Such appropriation is supported and mediated by the form of the book: Du Bois ends with an invocation to "God the Reader," who alone can ensure that "these crooked marks on a fragile leaf be not indeed THE END" (19).Double consciousness is also connected with embodiment, specifically the embodiment of African Americans, externalized and displaced in two images: blood, which I will discuss later in the essay, and the veil or caul that grants second sight. Like skin color, the caul is an inconsequential physical object invested with enormous symbolic power (8); it is a mark of origins that foretells the future. The "second sight" offered to the Negro is a vision of "two warring ideals," a vision that can barely be supported by "one dark body, whose dogged strength alone keeps it from being torn asunder"(9). At moments in The Souls of Black Folk, the veil is generalized, and becomes a physical barrier between the white world and the world of African American culture; the work of separating these worlds, of rendering them invisible to one another, is staged on the bodies of African Americans. The veil is usually seen as a separation between the races, something that has happened ("Feeling deeply and keenly the tendencies and opportunities of the age in which they live, their souls are bitter at the fate which drops the Veil... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Transformation of Hearts and Minds:Chan Zen-Catholic Approaches to PreceptsHarry L. WellsCatholic and Buddhist priests, monastics, teachers, and community leaders participated in the second of an anticipated four annual dialogues. The series is sponsored by the Dharma Realm Buddhist Association, the San Francisco Zen Center, and the United States Conference of Catholic Bishops (USCCB). The conference took place 4–7 March 2004 at Mercy Center in Burlingame, CA, whose own East-West (...) meditation program, led by Fr. Thomas Hand, celebrated its twentieth anniversary that year. A popular retreat center and home to the Sisters of Mercy of Burlingame, the Center offered participants tree-dotted, spacious grounds and strolling paths, as well as a labyrinth for contemplative walking.Each day began with both Catholics and Buddhists in Mercy Center's Rose Room, a Zen-style meditation space, for an hour of silent meditation in the morning. Catholic liturgy was celebrated in the afternoon in the main chapel, with all participants invited to attend and share prayer and blessings. On the two full days, Friday and Saturday, two sessions of presentations were held each morning, with one session following in the afternoon. Each of the six sessions focused on a position paper, with three papers given from a Buddhist and three from a Christian perspective. Each paper was presented by its authors, followed by two formal responses, one by a Buddhist and one by a Catholic participant. This was in turn followed by an open discussion within the whole group. A minute of silent meditation began and ended each session.The presentations focused on various meanings embraced by the term "precepts" in each tradition. One paper introduced perspectives on Buddhist precepts in three different Buddhist lineages. Another presented six guidelines as "Precepts on the [End Page 155] Mind-Ground" that connect ethical commitments with social engagement. A third paper focused on Bodhisattva practice, which embraces and unifies all sentient beings. On the Christian side, presentations discussed the precepts as signposts on the path that leads away from suffering, as motivations that move us, and as the practice of the presence of God, exemplified by the writings of Brother Lawrence.A glossary prepared by Fr. Francis Tiso helped define Catholic Christian terms for the Buddhist participants in the dialogue. Similarly, a book distributed to all participants by the Dharma Realm Buddhist Association provided background on "Buddhism A–Z." Formal discussion sessions in the evenings, as well as informal talks by the participants while walking outside or in the form of impromptu hallway meetings added to the depth and richness of the dialogue. Some recurring themes were the importance and meaning of a personal teacher in both traditions; another was the "embodiment" of the teachings, the value of teaching through presence. Personal stories and practical experiences offered by individual participants were much appreciated and added poetry and emotion to the headiness of theological discussion.Members of both the Buddhist and the Catholic traditions reported that the encounter with the spiritual practices and beliefs of the other faith provides both affirmation of the familiar and welcome discovery of unexpected riches of the spirit. The next meeting will be held 20–23 January 2005 at the San Francisco Zen Center. The theme will be "Practice: Method and Experience Toward Transformation."Participating in the 2004 dialogue were Rev. Heng Sure (Berkeley Buddhist Monastery), Bishop John C. Wester (Auxiliary Bishop, Archdiocese of San Francisco), Rev. Taigen Dan Leighton (Mountain Source Sangha), Fr. Arthur Kennedy (Secretariat for Ecumenical and Interreligious Affairs, USCCB), Bhikshuni Heng Liang (Dharma Realm Buddhist Association), Dr. Martin Verhoeven (Institute for World Religions), Dr. Ron Epstein (Institute for World Religions), Dr. Snjezana Akpinar (Dharma Realm Buddhist University), Rev. Shosan Victoria Austin (San Francisco Zen Center), Rev. Alan Senauke (Berkeley Zen Center), Jan Chozen Bays (Zen Community of Oregon), Sr. Phyllis D'Anna, SND (Center for the Practice of Applied Spirituality), Fr. Thomas W. Devereaux (Diocese of Santa Rosa), Robert Hale, OSB Cam. (Incarnation Monastery, Berkeley, CA), Thomas Hand, S.J. (Mercy Center, Burlingame, CA), Fr. Rafael Luévano (Diocese of Orange), Deacon Thomas McGowan (Diocese of Oakland), Lorraine Moriarity (St. Vincent de Paul Society of San Mateo County), Fr. Gerry O'Rourke (Archdiocese... (shrink)

A new reduction class is presented for the satisfiability problem for well-formed formulas of the first-order predicate calculus. The members of this class are closed prenex formulas of the form ∀ x∀ yC. The matrix C is in conjunctive normal form and has no disjuncts with more than three literals, in fact all but one conjunct is unary. Furthermore C contains but one predicate symbol, that being unary, and one function symbol which symbol is binary.

This article argues that the indefinite detention and torture of prisoners at the Guantanamo Bay Detention Camp and the intentional destabilization of Palestinian civilian life in the Israeli occupied Palestinian territories are indicative of the emergence of a new postmodern form of power. Coining the term homo dolorosus – the man who is available to be made to suffer – this article seeks to understand this emergent politics of suffering through a historicized reading of Foucault’s typology of power, informed by (...) the work of Giorgio Agamben. It is argued that, just as discipline was the dark inverse of the modern utopian Enlightenment project of universal democratic inclusion, the politics of suffering is the dark inverse of the postmodern biopolitical project of security. Using the work of Mikkel Joronen, Jasbir Puar and Lauren Wilcox as signposts, this article argues that homo dolorosus is produced by power’s encounter with a population that it perceives or represents as simultaneously risky and dependent. Moreover, it is suggested that homo dolorosus may be the manifestation of a project that aims to do away with freely-deciding subjectivity while keeping the human body alive. (shrink)

C.S. Lewis, the scholar of English mediaeval and Renaissance literature who died in 1963 and is still widely respected as a Christian apologist, complained that academic biblical scholars simply assume that miracles cannot have occurred in the fashion reported in the New Testament. In a lecture quoted by A.I.C. Heron 1 , he said: ‘The canon “If miraculous, unhistorical” is one they bring to their study of the texts, not one they have learned from it.’ In fact, as John Kent (...) retorted, they did not rule out in advance the idea of supernatural events, but were able, without it, to give adequate and plausible accounts of how the biblical documents reached their present form, by means of a method ‘based on questions of probability in terms of evidence’, not ‘on an a priori rejection of miracle’. 2 Conclusions concerning historical events of any kind are similarly based. ‘No historians’, says the historian R.J. Evans, ‘really believe in the absolute truth of what they are writing, simply in its probable truth, which they have done their utmost to establish by following the usual rules of evidence’. 3 To this question of ‘absolute’ truth I shall return. (shrink)

This article provides an overview of computer based catalogue systems designed for use by library clients, seeing present day ‘discovery systems’ on the same trajectory as the older ‘online public access catalogues’ which they are gradually replacing, both in technical development and their approach to client use scenarios. It traces the history of the OPAC/discovery system from its origins in the library automation of the 1960s through to the present and discusses the main technical standards which have formed its (...) development. The article goes on to consider questions relating to the usability of electronic library catalogues and highlights semiotic and ethical issues inherent to their design. It concludes with reflections on the future of the OPAC/discovery system in an information universe apparently dominated by the internet search engine. (shrink)

Evidence from a University of Zimbabwe oral history project suggests that many rural women in colonial Rhodesia played an active role in undermining patriarchal customs which they experienced as oppressive. These women defied family norms by choosing their own marriage partners, prioritizing the formal education of their daughters and finding ways to generate income to secure greater degrees of autonomy. This study compliments other research which depicts women's primary form of resistance to be moving from rural to urban areas, by (...) showing what options some women exercised while remaining within rural society. (shrink)

In vitro fertilisation is now an established technique for treating some forms of infertility, yet it remains ethically controversial. New developments, such as embryo donation and embryo freezing, have led to further discussion. We briefly discuss the ethical aspects of IVF, focusing on the issues of resource allocation, the 'unnaturalness' of the procedure, the moral status of the embryo, surrogate motherhood, and restrictions on access to IVF. We argue that, on the whole, IVF is an ethically justifiable method of assisting (...) infertile couples. (shrink)

The expectation is fulfilled, but in an unexpected way. 'The first studies toward this book were addressed to topics in the field of ethics' ; but our author, like Wagner composing 'Der Ring des Nibelungen', found himself becoming preoccupied with prolegomena. To these the present volume is wholly devoted. In order to establish its fundamental thesis that valuation is a form of empirical knowledge, two preparatory discussions are called for. An analysis of empirical knowledge in general is one of these; (...) but there is an inquiry properly prior even to this, an examination of the topic of meaning. The articulation of the book is accordingly tripartite; and Book I Meaning and Analytic Truth, Book II Empirical Knowledge, and Book III Valuation are of roughly equal length. (shrink)

There has only been sporadic engagement between the pragmatist and Marxist philosophical traditions. This is unfortunate because each has a great deal to learn from the other. This article seeks to form a bridge between the two traditions by reconstructing an argument from Marx and Engels for historical materialism in the light of both traditions' shared emphasis on the centrality of action. There is much in the Marxist tradition that pragmatists can and should integrate into their own work, particularly given (...) their interest in cultivating richer democracies. (shrink)

The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal (...) form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. (shrink)

The tree-based data structure of △-tree for propositional formulas is introduced in an improved and optimised form. The △-trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal (...) form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. (shrink)

Consider the following argument: All men are mortal; Socrates is a man; therefore, Socrates is mortal. Intuitively, what makes this a valid argument has nothing to do with Socrates, men, or mortality. Rather, each sentence in the argument exhibits a certain logical form, which, together with the forms of the other two, constitute a pattern that, of itself, guarantees the truth of the conclusion given the truth of the premises. More generally, then, the logical form of a sentence of natural (...) language is what determines both its logical properties and its logical relations to other sentences. The logical form of a sentence of natural language is typically represented in a theory of logical form by a well-formed formula in a ‘logically pure’ language whose only meaningful symbols are expressions with fixed, distinctly logical meanings (e.g., quantifiers). Thus, the logical forms of the sentences in the above argument would be represented in a theory based on pure predicate logic by the formulas ‘∀x(Fx ⊃ Gx)’, ‘Fy’, and ‘Gy’, respectively, where ‘F’, ‘G’, and ‘y’ are all free variables. The argument’s intuitive validity is then explained in virtue of the fact that the logical forms of the premises formally entail the logical form of the conclusion. The primary goal of a theory of logical form is to explain as broad a range of such intuitive logical phenomena as possible in terms of the logical forms that it assigns to sentences of natural language. (shrink)

In this paper I present a new theory of propositions, according to which propositions are abstract mathematical objects: well-formed formulas together with models. I distinguish the theory from a number of existing views and explain some of its advantages  chief amongst which are the following. On this view, propositions are unified and intrinsically truth-bearing. They are mind- and language-independent and they are governed by logic. The theory of propositions is ontologically innocent. It makes room for an (...) appropriate interface with formal semantics and it does not enforce an overly fine or overly coarse level of granularity. (shrink)

Akama et al. [1] systematically studied an arithmetical hierarchy of the law of excluded middle and related principles in the context of first-order arithmetic. In that paper, they first provide a prenex normal form theorem as a justification of their semi-classical principles restricted to prenex formulas. However, there are some errors in their proof. In this paper, we provide a simple counterexample of their prenex normal form theorem [1, Theorem 2.7], then modify it in an appropriate way which still (...) serves to largely justify the arithmetical hierarchy. In addition, we characterize a variety of prenex normal form theorems by logical principles in the arithmetical hierarchy. The characterization results reveal that our prenex normal form theorems are optimal. For the characterization results, we establish a new conservation theorem on semi-classical arithmetic. The theorem generalizes a well-known fact that classical arithmetic is $\Pi _2$ -conservative over intuitionistic arithmetic. (shrink)

We construct an extension P of the standard language of classical propositional logic by adjoining to the alphabet of a new category of logical-pragmatic signs. The well formed formulas of are calledradical formulas (rfs) of P;rfs preceded by theassertion sign constituteelementary assertive formulas of P, which can be connected together by means of thepragmatic connectives N, K, A, C, E, so as to obtain the set of all theassertive formulas (afs). Everyrf of P is (...) endowed with atruth value defined classically, and everyaf is endowed with ajustification value, defined in terms of the intuitive notion of proof and depending on the truth values of its radical subformulas. In this framework, we define the notion ofpragmatic validity in P and yield a list of criteria of pragmatic validity which hold under the assumption that only classical metalinguistic procedures of proof be accepted. We translate the classical propositional calculus (CPC) and the intuitionistic propositional calculus (IPC) into the assertive part of P and show that this translation allows us to interpret Intuitionistic Logic as an axiomatic theory of the constructive proof concept rather than an alternative to Classical Logic. Finally, we show that our framework provides a suitable background for discussing classical problems in the philosophy of logic. (shrink)

Nominalism in formal ontology is still the thesis that the only acceptable domain of quantification is the first-order domain of particulars. Nominalists may assert that second-order well-formed formulas can be fully and completely interpreted within the first-order domain, thereby avoiding any ontological commitment to second-order entities, by means of an appropriate semantics called “substitutional”. In this paper I argue that the success of this strategy depends on the ability of Nominalists to maintain that identity, and equivalence relations (...) more in general, is first-order and invariant. Firstly, I explain why Nominalists are formally bound to this first-order concept of identity. Secondly, I show that the resources needed to justify identity, a certain conception of identity invariance, are out of the Nominalist’s reach. (shrink)

A many-valued (aka multiple- or multi-valued) semantics, in the strict sense, is one which employs more than two truth values; in the loose sense it is one which countenances more than two truth statuses. So if, for example, we say that there are only two truth values—True and False—but allow that as well as possessing the value True and possessing the value False, propositions may also have a third truth status—possessing neither truth value—then we have a many-valued semantics in (...) the loose but not the strict sense. A many-valued logic is one which arises from a many-valued semantics and does not also arise from any two-valued semantics [Malinowski, 1993, 30]. By a ‘logic’ here we mean either a set of tautologies, or a consequence relation. We can best explain these ideas by considering the case of classical propositional logic. The language contains the usual basic symbols (propositional constants p, q, r, . . .; connectives ¬, ∧, ∨, →, ↔; and parentheses) and well-formed formulas are defined in the standard way. With the language thus specified—as a set of well-formed formulas—its semantics is then given in three parts. (i) A model of a logical language consists in a free assignment of semantic values to basic items of the non-logical vocabulary. Here the basic items of the non-logical vocabulary are the propositional constants. The appropriate kind of semantic value for a proposition is a truth value, and so a model of the language consists in a free assignment of truth values to basic propositions. Two truth values are countenanced: 1 (representing truth) and 0 (representing falsity). (ii) Rules are presented which determine a truth value for every proposition of the language, given a model. The most common way of presenting these rules is via truth tables (Figure 1). Another way of stating such rules—which will be useful below—is first to introduce functions on the truth values themselves: a unary function ¬ and four binary functions ∧, ∨, → and ↔ (Figure 2).. (shrink)

We study instantiated abstract argumentation frames of the form, where is an abstract argumentation frame and where the arguments x of S are instantiated by I as well formed formulas of a well known logic, for example as Boolean formulas or as predicate logic formulas or as modal logic formulas. We use the method of conceptual analysis to derive the properties of our proposed system. We seek to define the notion of complete extensions (...) for such systems and provide algorithms for finding such extensions. We further develop a theory of instantiation in the abstract, using the framework of Boolean attack formations and of conjunctive and disjunctive attacks. We discuss applications and compare critically with the existing related literature. (shrink)

Analysis of quantifiers in Wittgenstein's Tractatus. A critical survey In the Tractatus Logico-Philosophicus, Wittgenstein distinguishes between what can and cannot be said in any language by the general form of propositions. I explain Wittgenstein's method and discuss Robert J. Fogelin's criticism of what he takes to be the incompleteness of Wittgenstein's general form of propositions in his exposition of the 'Naive Constructivism of the Tractatus.' I argue that Fogelin's objection is mistaken, and that, contrary to Fogelin's claim, Wittgenstein's method when (...) properly applied produces all of the well-formed formulas with mixed multiple quantification that Fogelin maintains it cannot provide. I conclude by offering a critical comparison of similar solutions proposed, among others, by P.T. Geach, Scott Soames, and Matthias Varga von Kibéd. (shrink)

We study here equiformity, the standard identity criterion for sentences. This notion was put forward by Lesniewski, mentioned by Tarski and defined explicitly by Presburger. At the practical level this criterion seems workable but if the notion of sentence is taken as a fundamental basis for logic and mathematics, it seems that this principle cannot be maintained without vicious circle. It seems also that equiformity has some semantical features ; maybe this is not so clear for individual signs but sentences (...) are often considered as meaningful combinations of signs. If meaning has to play a role, we are thus maybe in no better position than when dealing with identity criterion for propositions. In formal logic, one speaks rather about well-formed formulas, but closed formulas are called sentences because they are meaningful in the sense that they can be true or false. Formulas look better like mathematical objects than material inscriptions and equiformity does not seem to apply to them. Various congruencies can be considered as identities between formulas and in particular "to have the same logical form". One can say that the objects of study of logic are rather logical forms than sentences conceived as material inscriptions. (shrink)

We investigate how the sentence choice semantics for propositional superposition logic developed in Tzouvaras could be extended so as to successfully apply to first-order superposition logic. There are two options for such an extension. The apparently more natural one is the formula choice semantics based on choice functions for pairs of arbitrary formulas of the basis language. It is proved however that the universal instantiation scheme of first-order logic, $\varphi \rightarrow \varphi $, is false, as a scheme of tautologies, (...) with respect to FCS. This causes the total failure of FCS as a candidate semantics. Then we turn to the other option, which is a variant of SCS, since it uses again choice functions for pairs of sentences only. This semantics however presupposes that the applicability of the connective | is restricted to quantifier-free sentences, and thus the class of well-formed formulas and sentences of the language is restricted too. Granted these syntactic restrictions, the usual axiomatizations of FOLS turn out to be sound and conditionally complete with respect to this second semantics, just like the corresponding systems of PLS. (shrink)

Let K = (p, q...; &, ∨, ~) be a zeroth-order formal language with sentence variables p, q..., two place connectives & (and), ∨ (or) and negation sign ~, and let F be the formula algebra (set of well-formed formulas in K defined in the standard way by induction from the sentence variables). If v is an assignment of truth values 1(true), 0(f alse) to the sentence variables p, q..., then classical propositional logic is characterized by extending (...) v by induction from p, q... to the formula algebra F in such a manner that the extension (called interpretation and also denoted by v) be a “homomorphism” from F into the two-element Boolean algebra B 2 ≡ (1, 0, ⋂, ⋃, ⊥), where “homomorphism” means that the following hold υ(q&p)=υ(q)∩υ(p)υ(q∨p)=υ(q)∪υ(p)υ(∼q)=υ(q)⊥. (shrink)

We present a multi-conclusion natural deduction calculus characterizing the dynamic reasoning typical of Adaptive Logics. The resulting system AdaptiveND is sound and complete with respect to the propositional fragment of adaptive logics based on CLuN. This appears to be the first tree-format presentation of the standard linear dynamic proof system typical of Adaptive Logics. It offers the advantage of full transparency in the formulation of locally derivable rules, a connection between restricted inference-rules and their adaptive counterpart, and the formulation of (...) abnormalities as a subtype of well-formed formulas. These features of the proposed calculus allow us to clarify the relation between defeasible and multiple-conclusion approaches to classical recapture. (shrink)

A constructive proof is given which shows that every nonrecursive r.e. many-one degree is represented by the family of decision problems for partial implicational propositional calculi whose well-formed formulas contain at most two distinct variable symbols.

This paper demonstrates the practical and philosophical strengths of adopting Luciano Floridi’s “general definition of information” (GDI) for use in the information sciences (IS). Many definitions of information have been proposed, but little work has been done to determine which definitions are most coherent or useful. Consequently, doubts have been cast on the necessity and possibility of finding a definition. In response to these doubts, the paper shows how items and events central to IS are adequately described by Floridi’s conception (...) of information, and demonstrates how it helps clarify the muddy theoretical framework resulting from the many previous definitions. To this end, it analyzes definitions, popular in IS, that conceive of information as energy, processes, knowledge, and physical objects. The paper finds that each of these definitions produces problematic or counterintuitive implications that the GDI suitably accounts for. It discusses the role of truth in IS, notes why the GDI is preferable to its truth-requiring variant, and ends with comments about the import of such a theory for IS research and practice. (shrink)

A logical system is studied whose well-formed representations consist of diagrams rather than formulas. The system, due to Shin [2, 3], is shown to be complete by an argument concerning maximally consistent sets of diagrams. The argument is complicated by the lack of a straight forward counterpart of atomic formulas for diagrams, and by the lack of a counterpart of negation for most diagrams.

We consider a quantifier-free language in which there are terms as well as formulas. The proposition-forming propositional operators are the usual ones, and the term-making term operators are the usual lattice theoretical ones. In addition there is a formula-making term operator, does. We study a new logic in which does is claimed to approximate some features of the informal concept the agent performs the action.

A well-known result states that, over basic Kalmar elementary arithmetic EA, the induction schema for ∑n formulas is equivalent to the uniform reflection principle for ∑n + 1 formulas . We show that fragments of arithmetic axiomatized by various forms of induction rules admit a precise axiomatization in terms of reflection principles as well. Thus, the closure of EA under the induction rule for ∑n formulas is equivalent to ω times iterated ∑n reflection principle. Moreover, (...) for k < ω, k times iterated ∑n reflection principle over EA precisely corresponds to the extension of EA by k nested applications of ∑n induction rule.The above relationship holds in greater generality than just stated. In fact, we give general formulas characterizing in terms of iterated reflection principles the extension of any given theory by k nested applications of ∑n or Πn induction rules. In particular, the closure of a theory T under just one application of ∑1 induction rule is equivalent to T together with ∑1 reflection principle for each finite Π2 axiomatized subtheory of T.These results have closely parallel ones in the theory of subrecursive function classes. The rules under study correspond, in a canonical way, to natural closure operators on the classes of provably recursive functions. Thus, ∑1 induction rule precisely corresponds to the primitive recursive closure operator, and ∑1 collection rule, introduced below, corresponds to the elementary closure operator. (shrink)

Each closed (i.e. variable free) formula of interpretability logic is equivalent in ILF to a closed formula of the provability logic G, thus to a Boolean combination of formulas of the form n.

Since the outbreak of the COVID-19 pandemic, the physical and mental health of older adults has been threatened. Promoting physical and mental health through physical activity has therefore become a strategy for healthy aging. In order to better understand the impact of the participation of older adults in physical activity, this paper selects different types of physical activity, and examines the relationship between them and subjective well-being through the analysis of the mediation effect of outdoor exercise environment and the (...) regulating effect of exercise form. In this cross-sectional study, a questionnaire survey was conducted in mainland China. The main data come from 903 older adults in five urban areas in Chengdu, Sichuan Province. The surveys were carried out using the Physical Activity Rating Scale, Newfoundland Subjective Well-Being Scale, Exercise Environment Scale, and Exercise Form Scale. SPSS was used for statistical analysis, linear regression analysis was adopted for processing data, and AMOS was used to establish a mediation model. The mediating variable is the outdoor exercise environment, and the moderating variable is exercise form; gender, age, education level, and monthly income were used as control variables. The study results showed that different physical activities were significantly, positively correlated with the subjective well-being of older adults ; among the activities, tai chi had the strongest effect on the subjective well-being of older adults. Outdoor exercise environment played a mediating role between different physical activity types and subjective well-being of older adults [tai chi: β = 0.030, 95% CI ; health qigong: β = 0.018, 95% CI ; walking and jogging: β = 0.034, 95% CI ]. Exercise form moderated the subjective well-being of older adults in different physical activities. The results of this study demonstrate that the outdoor exercise environment plays a mediating role between different physical activities and the subjective well-being of older adults, and the form of exercise can also moderate the impact of different physical activities on the subjective well-being of older adults. This study has enlightening significance for psychological intervention with older adults facing stress, anxiety and depression. (shrink)