This volume aims to offer an up-to-date indication of the on-going debate on the nature of logic. The focus is on questions pertaining to the existence and individuation of clear boundaries delineating the concerns of logic: What is their distinctive character? What makes logic a subject of its own, separate from (and generally in the background of) the concerns of other disciplines? What is it for an expression to be a logical constant? Or, perhaps equivalently, what (...) is it for an operation or a relation to be logical? Can these questions be addressed in a general setting, or are they intrinsically unanswerable except within specific frameworks of reference (e.g., a language, or a conceptual scheme)? How are they to be addressed—are they semantic, syntactic, pragmatic? And how do semantics, syntax, or pragmatics contribute to our understanding of these questions? Are the answers fully captured by extant systems of logic? Contributors: E. Bencivenga, J. van Benthem, D. van Dalen, M. García-Carpintero and M. Pérez Otero, A. P. Hazen, A. Koslow, G. Priest, G. Sher. (shrink)

This volume aims to offer an up-to-date indication of the on-going debate on the nature of logic. The focus is on questions pertaining to the existence and individuation of clear boundaries delineating the concerns of logic: What is their distinctive character? What makes logic a subject of its own, separate from (and generally in the background of) the concerns of other disciplines? What is it for an expression to be a logical constant? Or, perhaps equivalently, what (...) is it for an operation or a relation to be logical? Can these questions be addressed in a general setting, or are they intrinsically unanswerable except within specific frameworks of reference (e.g., a language, or a conceptual scheme)? How are they to be addressed—are they semantic, syntactic, pragmatic? And how do semantics, syntax, or pragmatics contribute to our understanding of these questions? Are the answers fully captured by extant systems of logic? Contributors: E. Bencivenga, J. van Benthem, D. van Dalen, M. García-Carpintero and M. Pérez Otero, A. P. Hazen, A. Koslow, G. Priest, G. Sher. (shrink)

In this paper Chateaubriand’s approach to solve some problems related to the nature of logic is confronted with the traditional approaches. It is shown that his hierarchy of logical types opens up new possibilities to characterize logical properties and logical truths and that it also sheds some new light on the foundations of mathematics.

In this article I engage with a recent debate vis-à-vis Kant’s conception of logic, which deals with whether Kant saw logical laws as normative for, or rather as constitutive of, the faculty of understanding. On the former view, logical laws provide norms for the correct exercise of the understanding; on the latter, they define the necessary structure of the faculty of understanding per se. I claim that these two positions are not mutually exclusive, as Kant held both a normative (...) and a constitutive conception of logic. I also sketch a parallelism between Kant’s conceptions of logic and of ethics: Kant’s twofold conception of logic parallels his view of moral laws as normative (for the human will) but constitutive (of a holy will). (shrink)

The paper examines the interrelationship between mathematics and logic, arguing that a central characteristic of each has an essential role within the other. The first part is a reconstruction of and elaboration on Paul Bernays’ argument, that mathematics and logic are based on different directions of abstraction from content, and that mathematics, at its core it is a study of formal structures. The notion of a study of structure is clarified by the examples of Hilbert’s work on the (...) axiomatization of geometry and Hilbert et al.’s formalist proof theory. It is further argued that the structural aspect of logic puts it under the purview of the mathematical, analogously to how the deductive nature of mathematics puts it under the purview of logic. This is then linked, in the second part, to certain aspects of Gödel’s critique of Carnap’s conventionalism, that ‘mere syntax’ cannot capture the full content of mathematics, which is revealed to be closely related to the characteristic of mathematics argued for by Bernays. Finally, this is connected with Gödel’s latter-day views about two kinds of formality, intensional and extensional, and the relationship between them. (shrink)

Max Cresswell and Hilary Putnam seem to hold the view, often shared by classical logicians, that paraconsistent logic has not been made sense of, despite its well-developed mathematics. In this paper, I examine the nature of logic in order to understand what it means to make sense of logic. I then show that, just as one can make sense of non-normal modal logics (as Cresswell demonstrates), we can make `sense' of paraconsistent logic. Finally, I turn (...) the tables on classical logicians and ask what sense can be made of explosive reasoning. While I acknowledge a bias on this issue, it is not clear that even classical logicians can answer this question. (shrink)

Here I revisit Bolzano's criticisms of Kant on the nature of logic. I argue that while Bolzano is correct in taking Kant to conceive of the traditional logic as a science of the activity of thinking rather than the content of thought, he is wrong to charge Kant with a failure to identify and examine this content itself within logic as such. This neglects Kant's own insistence that traditional logic does not exhaust logic as (...) such, since it must be supplemented by a transcendental logic that will in fact study nothing other than thought's content. Once this feature of Kant's views is brought to light, a much deeper accord emerges between the two thinkers than has hitherto been appreciated, on both the nature of the content that is at issue in logic and the sense of logic's generality and formality. (shrink)

Johannes Rudbeckius, one of Sweden’s most influential figures in theology, pedagogy, and church-state relations in the 17th century, published two books on logic: Logica ex optimis et præstantissimis autoribus collecta & conscripta and Controversiæ logices vel potius earum epitome. In this paper, I present and critically discuss Rudbeckius’s view on the nature of logic as it can be reconstructed from these two works. This requires, in particular, identifying the larger intellectual framework within which Rudbeckius operated. The single (...) most important philosopher having affected Rudbeckius’s ideas on logic is Jacopo Zabarella, which leads me to consider at some length the views on logic that Zabarella puts forward in his De Natura Logicæ. (shrink)

This detailed monograph deals with such problems as "The Unity of the Finite and Infinite," "Logic and the Concept of Function," "Mathematical Logic," "Formal and Dialectical Logic." The author mentions the work of Reichenbach and Lukasiewicz.--R. L. J.

The unique relation between logic and truth is crucial for understanding Fregean conception of logic. Frege has an insight that the nature of logic resides in the “truth“, which he finally locates in the assertoric-force of a sentence. Though Frege admits that assertoric-force is ineffable in ordinary language, he coins in his conceptual notation for such a force a much-disputed sign, i.e., judgment-stroke. In this paper, I will try to demonstrate that judgment-stroke is not adequate for (...) the task its inventor has assigned to it. Accordingly, it is misconceived and inconducive to clarify Frege’s vague insight into the protorelation. The mistake of judgment-stroke for the sign of assertoric-force has its root in Frege’s ignorance of the significant difference between “judgment” and assertion”, which will be elucidated at length in the light of Husserl’s theory of “doxic-modification“. In the end, based on a further elucidation of the activity of assertion, I will advance a tentative interpretation of the vague insight Frege has concerning the protorelation. (shrink)

I will analyse some properties of abduction that are essential from a logical standpoint. When dealing with the so-called ‘inferential problem’, I will opt for the more general concepts of input and output instead of those of premisses and conclusions, and show that in this framework two consequences can be derived that help clarify basic logical aspects of abductive reasoning: (i) it is more natural to accept the ‘multimodal’ and ‘context-dependent’ character of the inferences involved, (ii) inferences are not merely (...) conceived of in the terms of the process leading to the ‘generation of an output’ or to the proof of it, as in the traditional and standard view of deductive proofs, but rather, from this perspective abductive inferences can be seen as related to logical processes in which input and output fail to hold each other in an expected relation, with the solution involving the modification of inputs, not that of outputs. I will also describe that if we wish to naturalize the logic of the abductive processes and its special consequence relation, we should refer to the following main aspects: ‘optimization of situatedness’, ‘maximization of changeability’ of both input and output, and high ‘information-sensitiveness’. (shrink)

Cardinal Mercier’s Manual of Modern Scholastic Philosophy is a standard work, prepared at the Higher Institute of Philosophy, Louvain, mainly for the use of clerical students in Catholic Seminaries. Though undoubtedly elementary, it contains a clear, simple, and methodological exposition of the principles and problems of every department of philosophy, and its appeal is not to any particular class, but broadly human and universal. Volume II contains sections on natural theology, logic, ethics and outlines of the history of philosophy.

This book offers the first English translation of the _Quodlibetal Questions _of William of Ockham —reflections on a variety of topics in logic, ontology, natural philosophy, philosophical psychology, moral theory, and theology by one of the preeminent thinkers of the Middle Ages. It is based on the recent critical edition of Ockham’s theological and philosophical works.

This detailed monograph deals with such problems as "The Unity of the Finite and Infinite," "Logic and the Concept of Function," "Mathematical Logic," "Formal and Dialectical Logic." The author mentions the work of Reichenbach and Lukasiewicz.--R. L. J.

Logical realism, by Arthur Norman Prior understood as the view that logic is not about language but about reality, is a consistent and strong tenet in all of Prior's philosophical work. Recent disc...

In this article, I attempt once more to revisit the subject of logic in African philosophy or as some would have it, African logic. I discuss the views of those I call jingoists and irredentists and distance myself from them. I argue that there is logic in every human culture and language. I argue also that even the ancient Africans had logic in their languages. My goal is to show that logic as the tool of (...) thought is universal and not culture-bound. To do this, I will investigate the nature of logic and then examine again the notion of African logic before showing the relevance of logic to life. My method will be descriptive, prescriptive and analytical. Keywords : Logic, African logic, Irredentism, Afrocentrism, jingoism, African philosophy. (shrink)

I argue that Descartes and the Cartesians are likely in agreement that logic is an ars cogitandi whose aim is to perfect the ingenium by the exercise of its operations: ideating, judging, discoursing, and ordering. We can see that these elements are the underpinning of both the Regulae and the Discourse on Method, and thus, like Adrien Baillet and others in the seventeenth century, we can understand these two works as embodying Descartes’ “logic,” despite Descartes’ notorious anti-logic (...) Renaissance rhetoric in both writings. (shrink)

In her book Deviant Logic, Susan Haack argued for a “pragmatist” conception of logic. This conception holds that, logic is a theory on a par with other scientific theories, differing only from such theories by its degree of generality and the choice of a particular logic is to be made based on pragmatist principles, namely, economy, coherence, and simplicity. This view was contrasted, in this book, with an “absolutist” view of logic, according to which logical (...) laws are necessary and immune to revision. Two decades later, however, Haack acknowledged, in the Introduction to an enlarged version of the same book, that she would not approach the question of the revisability of logic in the same way she did earlier. What was missing in her first book was a distinction between the question of the necessity of the laws of logic and the question of our fallibility in recognizing which are the true laws of logic and what structures are essential to representation. She also acknowledged that this change was mainly influenced by Peirce, with whose work she had “only the most superficial acquaintance twenty years ago”. In this context, this paper has two aims: to show that, in Philosophy of Logics, we can find elements that reveal a tension between her early “pragmatic” views and her changing views on the nature of logic; to present some hypotheses about the role Peirce may have had in this change. (shrink)

This article deals with a question of a most general, comprehensive and profound content as it is the nature of mathematical–logical objects insofar as these are considered objects of knowledge and more specifically objects of formal mathematical theories. As objects of formal theories they are dealt with in the sense they have acquired primarily from the beginnings of the systematic study of mathematical foundations in connection with logic dating from the works of G. Cantor and G. Frege in (...) the last decades of the nineteenth century. Largely motivated by a phenomenologically founded view of mathematical objects/states-of-affairs, I try to consistently argue for their character as objects shaped to a certain extent by intentional forms exhibited by consciousness and the modes of constitution of inner temporality and at the same time as constrained in the form of immanent ‘appearances’ by what stands as their non-eliminable reference, that is, the world as primitive soil of experience and the mathematical intuitions developed in relations of reciprocity within-the-world. In this perspective and relative to my intentions I enter, in the last section, into a brief review of certain positions of G. Sher’s foundational holism and R. Tieszen’s constituted platonism, among others, respectively presented in Sher and Tieszen. (shrink)

As the foundation of our rationality, logic has traditionally been considered fixed, stable and constant. This conception of the discipline has been challenged recently by the plurality of logics and in this book, Pavel Arazim extends the debate to offer a new view of logic as dynamic and without a definite, specific shape. The Problem of Plurality of Logics examines the origins of our standard view of logic alongside Kant's theories, the holistic view, the issue of (...) class='Hi'>logic's pragmatic significance and Robert Brandom's logical expressivism. Arazim then draws on proof-theoretical approaches to present a convincing argument for a dynamic version of logical inferentialism, which opens space for a new freedom to modify our own logic. He explores the scope, possibilities and limits of this freedom in order to highlight the future paths logic could take, as a motivation for further research. Marking a departure from logical monism and also from the recent doctrine of logical pluralism in its various forms, this book addresses current debates concerning the expressive role of logic and contributes to a lively area of discussion in analytic philosophy. (shrink)

The PhD thesis advances a new approach to vagueness as dispersion, comparing it with the main philosophical theories of vagueness in the analytic tradition.