Nous examinons les conditions de vérité pour des attributions de savoir dans le cas des connaissances mathématiques. La disposition d’une démonstration formalisable semble être un critère naturel :(*) X sait que p est vrai si et seulement si X en principe dispose d’une démonstration formalisable pour p.La formalisabilité pourtant ne joue pas un grand rôle dans la pratique mathématique effective. Nous présentons des résultats d’une recherche empirique qui indiquent que les mathématiciens n’employent pas certaines spécifications de (*) quand ils attribuent (...) du savoir. De plus, nous montrons que le concept de savoir mathématique qui est à la base de l’emploi effectif du mot « savoir » de la pratique mathématique est tout à fait compatible avec certaines intuitions philosophiques mais apparaît comme différent des concepts philosophiques formant la base de (*). (shrink)

Nous examinons les conditions de vérité pour des attributions de savoir dans le cas des connaissances mathématiques. La disposition d’une démonstration formalisable semble être un critère naturel :(*) X sait que p est vrai si et seulement si X en principe dispose d’une démonstration formalisable pour p.La formalisabilité pourtant ne joue pas un grand rôle dans la pratique mathématique effective. Nous présentons des résultats d’une recherche empirique qui indiquent que les mathématiciens n’employent pas certaines spécifications de (*) quand ils attribuent (...) du savoir. De plus, nous montrons que le concept de savoir mathématique qui est à la base de l’emploi effectif du mot « savoir » de la pratique mathématique est tout à fait compatible avec certaines intuitions philosophiques mais apparaît comme différent des concepts philosophiques formant la base de (*). (shrink)

Fifty years of effort in artificial intelligence (AI) and the formalization of legal reasoning have produced both successes and failures. Considerable success in organizing and displaying evidence and its interrelationships has been accompanied by failure to achieve the original ambition of AI as applied to law: fully automated legal decision-making. The obstacles to formalizing legal reasoning have proved to be the same ones that make the formalization of commonsense reasoning so difficult, and are most evident where legal reasoning has to (...) meld with the vast web of ordinary human knowledge of the world. Underlying many of the problems is the mismatch between the discreteness of symbol manipulation and the continuous nature of imprecise natural language, of degrees of similarity and analogy, and of probabilities. (shrink)

This paper puts forward a new account of rigorous mathematical proof and its epistemology. One novel feature is a focus on how the skill of reading and writing valid proofs is learnt, as a way of understanding what validity itself amounts to. The account is used to address two current questions in the literature: that of how mathematicians are so good at resolving disputes about validity, and that of whether rigorous proofs are necessarily formalizable.

In order to explore the quantifiability and formalizability of uncertainty a wide range of uncertainties are investigated. They are summarized under eight main categories: factual, possibilistic, metadoxastic, agential, interactive, value, structural, and linguistic uncertainty. This includes both classical uncertainty and the uncertainties commonly called great, deep, or radical. For five of the eight types of uncertainty, both quantitative and non-quantitative formalizations are meaningful and available. For one of them (interactive uncertainty), only non-quantitative formalizations seem to be meaningful, and for (...) two (agential and structural uncertainty) neither quantitative nor non-quantitative formalization seems to be a useful approach. (shrink)

Introduction. The system of axioms for set theory to be exhibited in this paper is a modification of the axiom system due to von Neumann. In particular it adopts the principal idea of von Neumann, that the elimination of the undefined notion of a property (“definite Eigenschaft”), which occurs in the original axiom system of Zermelo, can be accomplished in such a way as to make the resulting axiom system elementary, in the sense of being formalizable in the logical calculus (...) of first order, which contains no other bound variables than individual variables and no accessory rule of inference (as, for instance, a scheme of complete induction).The purpose of modifying the von Neumann system is to remain nearer to the structure of the original Zermelo system and to utilize at the same time some of the set-theoretic concepts of the Schröder logic and of Principia mathematica which have become familiar to logicians. As will be seen, a considerable simplification results from this arrangement.The theory is not set up as a pure formalism, but rather in the usual manner of elementary axiom theory, where we have to deal with propositions which are understood to have a meaning, and where the reference to the domain of facts to be axiomatized is suggested by the names for the kinds of individuals and for the fundamental predicates.On the other hand, from the formulation of the axioms and the methods used in making inferences from them, it will be obvious that the theory can be formalized by means of the logical calculus of first order (“Prädikatenkalkul” or “engere Funktionenkalkül”) with the addition of the formalism of equality and the ι-symbol for “descriptions” (in the sense of Whitehead and Russell). (shrink)

Using a short excerpt from Anselm's Responsio as an example, this paper tries to present logical reconstruction as a special type of exegetical interpretation by paraphrase that is subject to (adapted) hermeneutic maxims and presumption rules that govern exegetical interpretation in general. As such, logical reconstruction will be distinguished from the non-interpretative enterprise of formalization and from the development of theories of logical form, which provide a framework in which formalization and reconstruction take place. Yet, even though logical reconstruction is (...) dependent on methods of formalization, it allows us to use formal methods for the analysis and assessment of natural language texts that are not readily formalizable and is thus an important tool when it comes to applying the concepts and methods of formal logic to such texts. (shrink)

This paper offers an elementary proof that formal arithmetic is consistent. The system that will be proved consistent is a first-order theory R♯, based as usual on the Peano postulates and the recursion equations for + and ×. However, the reasoning will apply to any axiomatizable extension of R♯ got by adding classical arithmetical truths. Moreover, it will continue to apply through a large range of variation of the un- derlying logic of R♯, while on a simple and straightforward translation, (...) the classical first-order theory P♯ of Peano arithmetic turns out to be an exact subsystem of R♯. Since the reasoning is elementary, it is formalizable within R♯ itself; i.e., we can actually demonstrate within R♯ (or within P♯, if we care) a statement that, in a natural fashion, asserts the consistency of R♯ itself. The reader is unlikely to have missed the significance of the remarks just made. In plain English, this paper repeals Goedel’s famous second theorem. (That’s the one that asserts that sufficiently strong systems are inadequate to demonstrate their own consistency.) That theorem (or at least the significance usually claimed for it) was a mis- take—a subtle and understandable mistake, perhaps, but a mistake nonetheless. Accordingly, this paper reinstates the formal program which is often taken to have been blasted away by Goedel’s theorems— namely, the Hilbert program of demonstrating, by methods that everybody can recognize as effective and finitary, that intuitive mathematics is reliable. Indeed, the present consistency proof for arithmetic will be recognized as correct by anyone who can count to 3. (So much, indeed, for the claim that the reliability of arithmetic rests on transfinite induction up to ε0, and for the incredible mythology that underlies it.). (shrink)

This essay proposes and defends a general thesis concerning the nature of fallacies of reasoning. These in distinctive ways are all said to be deductively invalid. More importantly, the most accurate, complete and charitable reconstructions of these species and specimens of the informal fallacies are instructive with respect to the individual character of each distinct informal fallacy. Reconstructions of the fallacies as deductive invalidities are possible in every case, if deductivism is true, which means that in every case they should (...) be formalizable in an expressively comprehensive formal symbolic deductive logic. The general thesis is illustrated by a detailed examination of Walter Burleigh's paradox in his c. 1323 work, De Puritate Artis Logicae Tractatus Longior (Longer Treatise on the Purity of Logic), as a challenge to the deductive validity of hypothetical syllogism. The paradox has the form, ‹If I call you a swine, then I call you an animal; if I call you an animal, then I speak truly; therefore, if I call you a swine, then I speak truly'. Several solutions to the problem are considered, and the inference is exposed as an instance of the common deductive fallacy of equivocation. (shrink)

Solovay has shown that if $\cal{O}$ is an open subset of $P(\omega)$ with code $S$ and no infinite set avoids $\cal{O}$ , then there is an infinite set hyperarithmetic in $S$ that lands in $\cal{O}$ . We provide a direct proof of this theorem that is easily formalizable in $ATR_0$.

We callsyntactic coding a technique which converts syntactic principles or constraints on representations into grammatical rules which can be implemented in any given rule grammar. In this paper we show that any principle or constraint on output trees formalizable in a certain fragment of dynamic logic over trees can be coded in this sense. This allows to reduce in a mechanical fashion most of the current theories of government and binding into GPSG-style grammars. This will be exemplified with Rizzi'sRelativized Minimality.

We establish by elementary proof-theoretic means the conservativeness of two subsystems of analysis over primitive recursive arithmetic. The one subsystem was introduced by Friedman [6], the other is a strengthened version of a theory of Minc [14]; each has been shown to be of considerable interest for both mathematical practice and metamathematical investigations. The foundational significance of such conservation results is clear: they provide a direct finitist justification of the part of mathematical practice formalizable in these subsystems. The results are (...) generalized to relate a hierarchy of subsystems, all contained in the theory of arithmetic properties, to a corresponding hierarchy of fragments of arithmetic. The proof theoretic tools employed there are used to re-establish in a uniform, elementary way relationships between various fragments of arithmetic due to Parsons, Paris and Kirby, and Friedman. (shrink)

The thesis aims at a methodological reflection of logical reconstruction and tries to develop this method in detail, especially with regard to the reconstruction of natural language arguments. First, the groundwork for the thesis is laid by presenting and, where necessary, adapting its foundations with regard to the philosophy of language and the theory of argument. Subsequently, logical reconstruction, especially the logical reconstruction of arguments, is presented as a hermeneutic method and as a tool for the application of (formal) logic (...) and argumentation theory to natural language arguments. Logical reconstruction is presented as a special type of exegetical interpretation by paraphrase that is subject to (adapted) hermeneutic maxims and presumption rules that govern exegetical interpretation in general. However, in contrast to the interpretation of texts by natural language paraphrases, logical reconstruction leads to interpretantia that are logically explicit formal language texts and can be analyzed using formal methods and meta-theoretical concepts that are not directly applicable to natural language texts. By providing explicit and precise records of different readings, logical reconstruction can thus help to clarify (and maybe even solve) persistent interpretation controversies. Through an adaptation and specification of hermeneutic maxims and presumption rules, the thesis aims at providing suitable means for the systematic guidance and evaluation of logical reconstructions of argumentative texts. As a genuinely interpretative undertaking, logical reconstruction will be distinguished from the non-interpretative enterprise of formalization and from the development of theories of logical form, which provide a framework in which formalization and reconstruction take place. As exegetical interpretations, logical reconstructions of texts that are not readily formalizable can still be assessed with respect to their hermeneutic quality. The hermeneutic method of logical reconstruction can thus widen the scope for the application of logic and argumentation theory, because it allows us to use formal methods for the analysis and assessment of "difficult" natural language texts in a non-arbitrary, albeit indirect way. The last part of the thesis presents a manual for the logical reconstruction of natural language arguments, whose application is illustrated step by step. (shrink)

Computational psychiatry is a quickly evolving discipline that aims to understand psychopathology in terms of computational, hence algorithmic processes. While cognitive phenomena, especially beliefs or ways of “reasoning”, can more easily be formalized, meaning re-described in mathematical terms and then entered computational models, there is speculation as to whether phenomenology might be formalizable too. In other words, there are speculations in terms of what aspects of the human experience, rather than specific cognitive processes alone, can enter computational models. Here, we (...) explore the possibility of formalizing and modeling a phenomenological account of schizophrenia, using the concepts of “minimal self” and “intentionality”. To test the applicability of these concepts for formalization and modeling, we first aim to clarify some misunderstandings around the very nature of minimal self and intentionality, namely: whether these concepts entail a “minimal” sense of self, or might be better described in “transparent” sensory-integration and information processing terms. We then try to apply the concepts to a computational logic based on Marr’s levels of description, a fundamental account for understanding the rationale of computational psychiatry. Overall, we are asking via what conditions phenomenology can enter a computational logic. (shrink)

Measures of theory-Distance are defined for theories formalizable within first-Order predicate logic by using distributive normal forms. The account is applied to give measures of verisimilitude.

Kurt Gödel with his work on the constructible universeLestablished the relative consistency of the Axiom of Choice and the Continuum Hypothesis. More broadly, he ensured the ascendancy of first-order logic as the framework and a matter of method for set theory and secured the cumulative hierarchy view of the universe of sets. Gödel thereby transformed set theory and launched it with structured subject matter and specific methods of proof. In later years Gödel worked on a variety of set theoretic constructions (...) and speculated about how problems might be settled with new axioms. We here chronicle this development from the point of view of the evolution of set theory as a field of mathematics. Much has been written, of course, about Gödel's work in set theory, from textbook expositions to the introductory notes to his collected papers. The present account presents an integrated view of the historical and mathematical development as supported by his recently published lectures and correspondence. Beyond the surface of things we delve deeper into the mathematics. What emerges are the roots and anticipations in work of Russell and Hilbert, and most prominently the sustained motif of truth as formalizable in the “next higher system”. We especially work at bringing out how transforming Gödel's work was for set theory. It is difficult now to see what conceptual and technical distance Gödel had to cover and how dramatic his re-orientation of set theory was. (shrink)

The belief in a world governed by natural law has meant that our ideas of good thinking have increasingly turned toward formalizable schemes, suitable to support ideas of consistency, accuracy, and disembodied clarity. The idea that thinking might be a bodily thing hasn't been much appreciated among philosophers of this tradition. Yet, we shall pursue this line of thought in this paper. It is suggested that knowledge is not something we have but something created in the very moment of use. (...) The same goes for other essential concepts such as for instance causality. Causality is seen as a human bodily experience. Causality is an experience, and from this fact follows that the Newtonian world must be turned upside down. The laws of gravity are not something "out-there" but something "in-here". (shrink)

A well-known polymodal provability logic inlMMLBox due to Japaridze is complete w.r.t. the arithmetical semantics where modalities correspond to reflection principles of restricted logical complexity in arithmetic. This system plays an important role in some recent applications of provability algebras in proof theory. However, an obstacle in the study of inlMMLBox is that it is incomplete w.r.t. any class of Kripke frames. In this paper we provide a complete Kripke semantics for inlMMLBox . First, we isolate a certain subsystem inlMMLBox (...) of inlMMLBox that is sound and complete w.r.t. a nice class of finite frames. Second, appropriate models for inlMMLBox are defined as the limits of chains of finite expansions of models for inlMMLBox . The techniques involves unions of n -elementary chains and inverse limits of Kripke models. All the results are obtained by purely modal-logical methods formalizable in elementary arithmetic. (shrink)

We aim to compile some means for a rational reconstruction of a named part of the start-over of Baruch (Benedictus) de Spinoza's metaphysics in 'de deo' (which is 'pars prima' of the 'ethica, ordine geometrico demonstrata' ) in terms of 1st order model theory. In so far, as our approach will be judged successful, it may, besides providing some help in understanding Spinoza, also contribute to the discussion of some or other philosophical evergreen, e.g. 'ontological commitment'. For this text we (...) assume the reader familiar with 'de deo' as well as with some basic concepts and results of 1st order model theory. Before we start reconstruction, we will first revisit shortly the concept of 'attributum' (definitio IV) in it's setting in 'de deo' , next scan for formalizable aspects of 'in suo genere finita' ('de deo', definitio II), subsequently list the model theoretic constructs we will make use of. Then we begin reconstruction by stating "coordinative definitions" for the notions of 'attribute (of a substance)', 'modus (as conceived via an attribute)' and 'substance (as conceived via an attribute)', reasoning shortly for each of them. The "coordinative definitions", we will arrive at, must not be understood as literal translations of Spinoza's concepts - of course, there can't be such a thing as a literal translation - they are meant as formal analoga of these concepts, mapping some logical structure. But even with this caveat they may seem strange to the reader at this stage of discussion. Additional justification for them then should be found in our endeavour, to map some argumentation of Spinoza's proofs of some of his propositions from this starting point. -/- [ Version 1 of this paper originated from 2020-03-14. This is version 2 from 2021-09-12 with some readability amendments. ]. (shrink)

Quantum-mechanical event descriptions are context-dependent descriptions. The role of quantum (nondistributive) logic is in the partial ordering of contexts rather than in the ordering of quantum-mechanical events. Moreover, the kind of quantum logic displayed by quantum mechanics can be easily inferred from the general notion of contextuality used in ordinary language. The formalizable core of Bohr's notion of complementarity is the type of context dependence discussed in this paper.

We provide a new and elementary proof of strong normalization for the lambda calculus of intersection types. It uses no strong method, like for instance Tait-Girard reducibility predicates, but just simple induction on type complexity and derivation length and thus it is obviously formalizable within first order arithmetic. To obtain this result, we introduce a new system for intersection types whose rules are directly inspired by the reduction relation. Finally, we show that not only the set of strongly normalizing terms (...) of pure lambda calculus can be characterized in this system, but also that a straightforward modification of its rules allows to characterize the set of weakly normalizing terms. (shrink)

In this paper, we suggest the broader concept of proof-event, introduced by Joseph Goguen, as a fundamental methodological tool for studying proofs in history of mathematics. In this framework, proof is understood not as a purely syntactic object, but as a social process that involves at least two agents; this highlights the communicational aspect of proving. We claim that historians of mathematics essentially study proof-events in their research, since the mathematical proofs they face in the extant sources involve many informal (...) components, often not completely formalizable, and convey some kind of semantic content calling for understanding and verification. We illustrate the application of this methodological approach in some outstanding historical cases, paying particular attention to the process of proof interpretation that makes a proof-event alive. Finally, we suggest a classification of proof-events, according to the conditions imposed upon problem-solving. This enables us to speak about broad classes of proof-events in history of mathematics that share a common characteristic. (shrink)

Addresses the substantive issues raised by J. E. Staddon's (see record 1985-04009-001) alternative models of causality, in response to Staddon's displeasure with what he claimed to be the present author's (see record 1983-22326-001) formalization of causal structures. The major question at issue is not the formalizability of causal processes but whether cognitive determinants of behavior are reducible to past stimulus inputs in causal structures. Evidence indicates that the residuum of past stimuli cannot serve as an adequate proxy for cognitive (...) processes, which largely involve propositional knowledge and cognitive operations on what one knows. (shrink)

Nothing that can be called thinking is formalized or formalizable; nor can it be likened to a mechanical process (Church's hypothesis). Rather, thinking sets into motion human imagination and passion.Having already written extensively on the imagination,' I will limit myself here to outlining its basic structure. At the two opposite poles of knowledge, as well as in its center, lies the creative power of the human being, that is, radical imagination. It is thanks to the imagination that the world is (...) presented in this form and not in some other: it is imagination that creates axioms, postulates, and the fundamental patterns that subtend the structures of knowledge; finally, it is imagination that both furnishes the hypothetical models and idea-images of knowledge, and makes possible their potential development and/or insight into them. This imagination, however, both in itself and in its essential operations – which include its social forms, experienced on this level as the creation of an anonymous collective force – is neither formalized nor formalizable. Obviously, the imagination contains – just as does everything else that exists – a totalizing, identity-bearing dimension (which for brevity's sake we have elsewhere called ensidiqt,ce)2; but this dimension of the imagination is not the essential one, neither in its operations nor its results, no more than the arithmetic relations between tones are the essential element of a Bach fugue. (shrink)

This volume of essays addresses the main problem confronting an epistemology for mathematics; namely, the nature and sources of mathematical justification. Attending to both particular and general issues, the essays, by leading philosophers of mathematics, raise important issues for our current understanding of mathematics. Is mathematical justification a priori or a posteriori? What role, if any, does logic play in mathematical reasoning or inference? And of what epistemological importance is the formalizability of proof? The editor, Michael Detlefsen, has brought (...) together an outstanding collection of essays, only one of which has previously appeared. It will be essential for philosophers and historians of mathematics, as well as philosophically inclined logicians and philosophers interested in the nature of reasoning and justification. A companion volume entitled Proof, Logic and Formalization, edited by Michael Detlefsen, is also available from Routledge. (shrink)

In this interview with Yann Moulier Boutang and Carlo Vercellone, André Gorz elaborates on three crucial points of his analysis of the significance of the mutation inherent in the concept of cognitive capitalism: first, the redefinition of the mechanisms of exploitation and the processes of emancipation, since when labor is no longer measurable in units of time, and when self-exploitation takes on a central function in the process of valorization, the production of subjectivity becomes a central site of conflicts; second (...) the importance of snaking a precise distinction between the notion of knowledge, which is objective and formalizable by essence, and the notion of « know-how » or intellectual capability, which is by essence something alive and experienced; third the subjective and objective reasons why cognitive capitalism appears as a crisis of capitalism, containing the seed of another model of society. (shrink)

Sambin [6] proved the normalization theorem for GL, the modal logic of provability, in a sequent calculus version called by him GLS. His proof does not take into account the concept of reduction, commonly used in normalization proofs. Bellini [1], on the other hand, gave a normalization proof for GL using reductions. Indeed, Sambin's proof is a decision procedure which builds cut-free proofs. In this work we formalize this procedure as a recursive function and prove its recursiveness in an arithmetically (...) formalizable way, concluding that the normalization of GL can be formalized in PA. MSC: 03F05, 03B35, 03B45. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Is Literature Self-Referential?Eric MillerIIs literary language necessarily self-referential? And does this put paradox at the heart of literature? For at least two decades now, affirmative answers to both questions have been articles of faith among critics in the structuralist and poststructuralist mainstream. Literature’s ineluctable paradoxicality attracts us so because a paradox suggests that there are limits to human rationality, and thus strikes a blow for literature and against science. (...) Paradox ensures literature its own special realm, safe from the culturally imperialistic inroads of science’s orderly, rational-empirical constructions. Literature thus gets to be seen as “bigger” than reason, because only literature can live with paradox, and thus only literature reveals those “deeper” truths of contradiction-ridden human existence, whereas science can never penetrate beyond rational manipulations of phenomenal surfaces. Indeed, for anyone who holds all human existence to be fundamentally paradoxical, this special capacity makes literature the only genuine, demystified species of human knowledge. In the war between C. P. Snow’s Two Cultures, a war humanists are now losing badly, we like to regard paradox as our ultimate weapon.Belief in the paradoxicality of literature may also be found among the New Critics, 1 and in fact goes back at least to the Romantics, 2 but they did not derive this belief from a necessary self-referentiality of literary language. This newer way of deriving paradox appears to offer several competitive advantages. Self-reference seems to be the ultimate version of “art for art’s sake”: if all literary language is necessarily self-referential, then literature must be something totally self-contained, and is thus legitimized solely in and through itself. In addition, deriving [End Page 475] literature’s paradoxicality from self-reference seems to ground it in the same conceptual realm as mathematical logic, and thus tempts us to claim for literature a “rigor” normally conceded only to logic, mathematics, and theoretical physics. Self-referentiality would thus seem both to protect literature’s autonomy and to raise its cultural status into the company of mathematics and science.But it is a trap. For behind this new strategy lurks a capitulation to the underlying conceptual scheme of natural science, and literature thus comes to be conceived, in effect, as a science. Self-reference is, after all, still a kind of reference; paradox is still a kind of truth-relational construction;—and truth-relations built around reference constitute the correspondence theory of truth. From such a foundational commitment to reference and correspondence-truth, flows the rest of the scientific worldview: the dualism of referring expression and referent, word and object, sentence and fact, theory and data, language and world, culture and nature. The presentation of literature as a quasi-negation of this ontology changes nothing. The dualism of reference still functions as literature’s conceptual starting point, as its arche. We only appear to be defining a peculiar and radically distinct sphere for literature when we insist on its self-referentiality, on the (recursive) identity, for it, of referring expression and referent. For, this is still to treat the conceptual distinction between the two as foundational, and literature thereby tacitly assimilates science’s fundamental categorial division: the referential language-world duality of correspondence truth. Indeed, literature thus comes to live even more completely in the margins of science: it will have no essence of its own; it will differ at most in being a photo-negative image of science’s positiv(istic) project. In Snow’s war, self-reference is a Trojan horse.With self-reference as the essence of literature, we are thus staking our reputations on literature’s being a special field of formalizable “knowledge about...,” rather than, say, a quality or kind or realm of possible experience—which is to adopt science’s understanding of what is important. Matters are only made worse by that other attempt to define literary studies as a negation of the theory-data dualism of natural science: the poststructuralist denial of the distinction between criticism and literature. For the institutional need professional critics have to be seen as a discipline with a method and a subject, as a form of “knowledge about,” hardly disappears with... (shrink)

Rudolf Carnap defended two quite different critiques of traditional philosophy: in addition to the much discussed verifiability criterion, he also proposed a critique based upon "formalizability." Formalizability rests upon the principle of tolerance plus an acceptance of a linguistic methodology. Standard interpreters of Carnap (e.g., [7] and [8]) assume that the principle of tolerance (and, hence, formalizability) gains its argumentative support from verificationism. Carnap, in fact, kept the two critiques separate and independent. Indeed, verificationism is even, in (...) spirit, inconsistent with tolerance. If the formalizability approach is emphasized, traditional metaphysics is reconstructed, not banished. Philosophical disputes remain rationally decidable, but metatheoretical in nature. Two results follow: Carnap's metaphilosophy cannot be rejected merely on the basis of rejections of verifiability. Second, Carnap's conclusion that all philosophy concerns language provides no reason for despair. (shrink)

Manfred Eigen employs the terms language and communication to explain key recombination processes of DNA as well as to explain the self-organization of human language and communication: Life processes as well as language and communication processes are governed by the logic of a molecular syntax, which is the exact depiction of a principally formalizable reality.

We discuss a theory presented in a posthumous paper by Alfred Tarski entitled “What are logical notions?”. Although the theory of these logical notions is something outside of the main stream of logic, not presented in logic textbooks, it is a very interesting theory and can easily be understood by anybody, especially studying the simplest case of the four basic logical notions. This is what we are doing here, as well as introducing a challenging fifth logical notion. We first recall (...) the context and origin of what are here called Tarski-Lindenbaum logical notions. In the second part, we present these notions in the simple case of a binary relation. In the third part, we examine in which sense these are considered as logical notions contrasting them with an example of a nonlogical relation. In the fourth part, we discuss the formulations of the four logical notions in natural language and in first-order logic without equality, emphasizing the fact that two of the four logical notions cannot be expressed in this formal language. In the fifth part, we discuss the relations between these notions using the theory of the square of opposition. In the sixth part, we introduce the notion of variety corresponding to all non-logical notions and we argue that it can be considered as a logical notion because it is invariant, always referring to the same class of structures. In the seventh part, we present an enigma: is variety formalizable in first-order logic without equality? There follow recollections concerning Jan Woleński. This paper is dedicated to his 80th birthday. We end with the bibliography, giving some precise references for those wanting to know more about the topic. (shrink)

Manfred Eigen employs the terms language and communication to explain key recombination processes of DNA as well as to explain the self-organization of human language and communication: Life processes as well as language and communication processes are governed by the logic of a molecular syntax, which is the exact depiction of a principally formalizable reality. The author of the present contribution demonstrates that this view of Manfred Eigen’s cannot be sufficiently substantiated and that it must be supplemented by an approach (...) based on linguistic pragmatics. (shrink)

We show that every model of IΔ0 has an end extension to a model of a theory where log-space computable function are formalizable. We also show the existence of an isomorphism between models of IΔ0 and models of linear arithmetic LA.

This essay aims to provide a modal logic for rational intuition. Similarly to treatments of the property of knowledge in epistemic logic, I argue that rational intuition can be codified by a modal operator governed by the modal $\mu$-calculus. Via correspondence results between fixed point modal propositional logic and the bisimulation-invariant fragment of monadic second-order logic, a precise translation can then be provided between the notion of 'intuition-of', i.e., the cognitive phenomenal properties of thoughts, and the modal operators regimenting the (...) notion of 'intuition-that'. I argue that intuition-that can further be shown to entrain conceptual elucidation, by way of figuring as a dynamic-interpretational modality which induces the reinterpretation of both domains of quantification and the intensions and hyperintensions of mathematical concepts that are formalizable in monadic first- and second-order formal languages. Hyperintensionality is countenanced via a topic-sensitive epistemic two-dimensional truthmaker semantics. (shrink)

Inspired by some logical considerations, the paper proposes a novel perspective on the use of two-players zero-sum games in abstract argumentation. The paper first introduces a second-order modal logic, within which all main Dung-style semantics are shown to be formalizable, and then studies the model checking game of this logic. The model checking game is then used to provide a systematic game theoretic proof procedure to test membership with respect to all those semantics formalizable in the logic. The paper discusses (...) this idea in detail and illustrates it by providing a game for the so-called skeptical preferred and skeptical semi-stable semantics. (shrink)

We introduce a nonstandard arithmetic $NQA^-$ based on the theory developed by R. Chuaqui and P. Suppes in [2] (we will denote it by $NQA^+$ ), with a weakened external open minimization schema. A finitary consistency proof for $NQA^-$ formalizable in PRA is presented. We also show interesting facts about the strength of the theories $NQA^-$ and $NQA^+$ ; $NQA^-$ is mutually interpretable with $I\Delta_0 + EXP$ , and on the other hand, $NQA^+$ interprets the theories IΣ1 and $WKL_0$.

Scientific research in the formal sciences comes in multiple degrees of formality: fully formal work; rigorous proofs that practitioners know to be formalizable in principle; and informal work like rough proof sketches and considerations about the advantages and disadvantages of various formal systems. This informal work includes informal and semi-formal debates between formal scientists, e.g. about the acceptability of foundational principles and proposed axiomatizations. In this paper, we propose to use the methodology of structured argumentation theory to produce a formal (...) model of such informal and semi-formal debates in the formal sciences. For this purpose, we propose ASPIC-END, an adaptation of the structured argumentation framework ASPIC+ which can incorporate natural deduction style arguments and explanations. We illustrate the applicability of the framework to debates in the formal sciences by presenting a simple model of some arguments about proposed solutions to the Liar paradox, and by discussing a more extensive—but still preliminary—model of parts of the debate that mathematicians had about the Axiom of Choice in the early twentieth century. (shrink)

Penrose proved that a computational or formalizable theory of the brainís cognitive functioning is impossible, but suggested that a physical non-computational and non-formalizable one may be viable. Arguments as to why Penroseís program is unrealizable are presented. The main argument is that a non-formalizable theory should be verbal. However, verbal paradoxes based on Cantorís diagonal processes show the impossibility of a consistent verbal theory of the brain comprising its arithmetical cognition. It is suggested that comprehensive theories of the human brain (...) and of physical experience are Kantian rather than Platonic ideas. This suggestion is likewise based on arguments related to diagonal processes. (shrink)

Desde la perspectiva abierta por este libro no puede ya el estudio del Ser considerarse patrimonio de aquellas concepciones que lo entienden exento de contradicción, de gradualidad y de inserción en el devenir. Perfilase ahora una visión del Ser y de los seres que, a la vez que reconoce la absoluta realidad de aquél, concibe todo lo real con determinaciones mutuamente contradictorias, en un entretejimiento de ser y no-ser; visión que viene defendida adoptando el estilo de pensamiento de la filosofía (...) analítica: un proceder, hasta donde quepa, por argumentos formalizables y por definiciones rigurosas. Van desfilando ante esa instancia metodológica los grandes problemas de la metafísica, desembocándose en un racionalismo ontológico consecuente, a la vez que dialéctico. Pruébase, con un argumento trascendental, un principio de inteligibilidad de lo real, del cual van resultando los de razón suficiente, no-contradicción y tercio excluso; explicándose cómo, y en qué medida, coexiste su vigencia con la de lo contradictorio, en una realidad donde se cumple el principio de gradualidad: todas las diferencias son de grado. (shrink)

At some step in proving the Liar Paradox in natural language, a sentence is derived that seems overdetermined with respect to its semantic value. This is complemented by Tarski’s Theorem that a formal language cannot consistently contain a naive truth predicate given the laws of logic used in proving the Liar paradox. I argue that proofs of the Eubulidean Liar either use a principle of truth with non-canonical names in a fallacious way or make a fallacious use of substitution of (...) identicals. Tarski never committed the first fallacy and may have himself considered it fallacious. Nevertheless, I clarify that it is fallacious. I then argue substitution of identicals needs to be restricted within the scope of the truth predicate. A logic for truth implementing this restriction is a monotonic extension of a classical first order logic, or indeed a formalizable fragment of natural language. Proofs of Tarski’s Indefinability of Truth theorem are invalid in this logic. This approach generalizes to invalidate proofs of Liar-like paradoxes, particularly the predicate form of the Knower paradox. Consequently, such a logic can be further extended in a way that avoids Montague’s theorem for such a system. Yet, the semantic status of a Liar sentence is not fully resolved. It is no longer overdetermined; it is now underdetermined. (shrink)

Inasmuch as physical theories are formalizable, set theory provides a framework for theoretical physics. Four speculations about the relevance of set theoretical modeling for physics are presented: the role of transcendental set theory (i) in chaos theory, (ii) for paradoxical decompositions of solid three-dimensional objects, (iii) in the theory of effective computability (Church-Turing thesis) related to the possible “solution of supertasks,” and (iv) for weak solutions. Several approaches to set theory and their advantages and disadvatages for physical applications are discussed: (...) Canlorian “naive” (i.e., nonaxiomatic) set theory, contructivism, and operationalism. In the author's opinion, an attitude of “suspended attention” (a term borrowed from psychoanalysis) seems most promising for progress. Physical and set theoretical entities must be operationalized wherever possible. At the same time, physicists should be open to “bizarre” or “mindboggling” new formalisms, which need not be operationalizable or testable at the lime of their creation, but which may successfully lead to novel fields of phenomenology and technology. (shrink)

Sambin [6] proved the normalization theorem for GL, the modal logic of provability, in a sequent calculus version called by him GLS. His proof does not take into account the concept of reduction, commonly used in normalization proofs. Bellini [1], on the other hand, gave a normalization proof for GL using reductions. Indeed, Sambin's proof is a decision procedure which builds cut-free proofs. In this work we formalize this procedure as a recursive function and prove its recursiveness in an arithmetically (...) formalizable way, concluding that the normalization of GL can be formalized in PA. MSC: 03F05, 03B35, 03B45. (shrink)

The worry that our actions are not free because they are compelled by their causal antecedents is addressed. The everyday notion of cause is a mix of different elements, and it has taken science a long time to develop a mature concept that separates out the objective content, providing us with a clean, precise, formalizable notion freed of the subjective and phenomological components. This chapter is about the historical developments that led to that notion, culminating in the interventionist conception of (...) causation, accompanied by complementary developments in our understanding of the function of causal thinking. It is argued causation appears in mature science not as necessary connections written into the fabric of nature, but robust pathways that can be utilized as strategic routes to bringing about ends. Causal relations, in this form, function not as challenges to freedom, but handmaids to decision. (shrink)

This study, The Dialectic of Discovery, addresses the long-standing debate about the possibility of a "logic of discovery." Regarding this issue, four interlocking theses are defended. The first thesis is that there is indeed a logic of discovery, namely, dialectic, which is an extension of underlying inference and question logics. ;The second thesis is that this fact has been overlooked because the view of knowledge that has dominated Western philosophy, a view I dub "the solipsistic concept of knowledge," blinds us (...) to it. ;The third thesis is that this dialectic is to a large degree formalizable, and that it ought to be formalized to the extent possible. ;The fourth thesis is that the main block to complete formalizability is a particular sort of context-dependency, namely dependence upon the physical conditions under which research is conducted; however, this particular context-sensitivity, this irreducible pragmatic element, is isolatable within the dialectical system as the rules of strategy . Nature does not dictate what is rational, but she does dictate how that rationality should be applied if it is to be successful. ;The structure of the work is designed to present the defense of those theses as closely to their stated order as possible. In the first two chapters, I lay the groundwork for a reasonable defense of Thesis 1 by discussing both ends of the phrase "the logic of discovery." Then, in Chapter Three, I address Thesis 1 directly. ;Thesis 2 is introduced in Chapter Five, and explored more fully in Chapter Fourteen. ;Theses 3 and 4 require the most sustained defense. Since dialectic is an extension of underlying assetoric and erotetic components, Chapters Four and Six address assertoric matters, while Chapter Seven addresses erotetics. ;The assertoric and erotetic foundations having been laid, I am able in Chapters Eight and Nine to exhibit in some detail a formal dialectic of sufficient power to explicate discovery. After exploring conceptual change in the light of dialectic, we are able to address Thesis 4 directly in Chapter Thirteen. ;I conclude the study by examining Thesis 2 in Chapter Fourteen. (shrink)

The present paper deals with natural intuitionistic semantics for intuitionistic logic within an intuitionistic metamathematics. We show how strong completeness of full first order logic fails. We then consider a negationless semantics à la Henkin for second order intuitionistic logic. By using the theory of lawless sequences we prove that, for such semantics, strong completeness is restorable. We argue that lawless negationless semantics is a suitable framework for a constructive structuralist interpretation of any second order formalizable theory (classical or intuitionistic, (...) contradictory or not). (shrink)

An examination of four types of logico-mathematical formalisms, conceived as attempts to avoid paradoxes, leads to the conclusion that there can be no general, formal criterion of nonsense. Crahay holds that formal systems must be treated as dynamic, as the not-fully-formalizable becoming formal, the "conceptual" becoming "notional." Though technically competent and based on a vast amount of material, the treatment is too diffuse and sketchy to be more than suggestive.--L. K. B.

An examination of four types of logico-mathematical formalisms, conceived as attempts to avoid paradoxes, leads to the conclusion that there can be no general, formal criterion of nonsense. Crahay holds that formal systems must be treated as dynamic, as the not-fully-formalizable becoming formal, the "conceptual" becoming "notional." Though technically competent and based on a vast amount of material, the treatment is too diffuse and sketchy to be more than suggestive.--L. K. B.

This paper presents examples of infinite diagrams (as well as infinite limits of finite diagrams) whose use is more or less essential for understanding and accepting various proofs in higher mathematics. The significance of these is discussed with respect to the thesis that every proof can be formalized, and a "pre" form of this thesis that every proof can be presented in everyday statements-only form.