This paper examines the metaphysical status of Ezumezu logic in the direction of logical realism. While presenting Ezumezu logic as a prototype of African logic, Chimakonam makes statements that somewhat entail logical monism. Using the method of critical analysis of related literature, the paper argues that presenting Ezumezu logic as one of the prototypes of African logic while at the same time making claims that elevate it to a hegemonic status, gives rise to what is regarded in (...) the paper as the monist-pluralist paradox. Drawing lessons from Abakedi’s ID paradox, the paper argues that a monist logical foundation for African logic cannot be consistently defended without paradoxes. The paper proposes that different African philosophies should be grounded by different African logics such that one need not be trained in one particular prototype such as Ezumezu logic or argue in conformity to it to qualify as an African professional or scholar. (shrink)

Abstract‘Logical Realism’ is taken to mean many different things. I argue that if reality has a privileged structure, then a view I call metaphysical logical realism is true. The view says that, first, there is ‘One True Logic’; second, that the One True Logic is made true by the mind‐and‐language‐independent world; and third, that the mind‐and‐language‐independent world makes it the case that the One True Logic is better than any other logic at capturing the structure of (...) reality. Along the way, I discuss a few alternatives, and clarify two distinct kinds of metaphysical logical realism. (shrink)

Logical realism is the view that there is logical structure in the world. I argue that, if logical realism is true, then we are deeply ignorant of that logical structure: either we can’t know which of our logical concepts accurately capture it, or none of our logical concepts accurately capture it at all. I don’t suggest abandoning logical realism, but instead discuss how realists should adjust their methodology in the face (...) of this ignorance. (shrink)

The paper compares two theories of the nature of logic: Penelope Maddy's and my own. The two theories share a significant element: they both view logic as grounded not just in the mind (language, concepts, conventions, etc.), but also, and crucially, in the world. But the two theories differ in significant ways as well. Most distinctly, one is an anti-holist, "austere naturalist" theory while the other is a non-naturalist "foundational-holistic" theory. This methodological difference affects their questions, goals, orientations, the scope (...) of their investigations, their logical realism (the way they ground logic in the world), their explanation of the modal force of logic, and their approach to the relation between logic and mathematics. The paper is not polemic. One of its goal is a perspicuous description and analysis of the two theories, explaining their differences as well as commonalities. Another goal is showing that and how (i) a grounding of logic is possible, (ii) logical realism can be arrived at from different perspectives and using different methodologies, and (iii) grounding logic in the world is compatible with a central role for the human mind in logic. (shrink)

This paper argues against Logical Realism, in particular against the view that there are facts of matters of logic that obtain independently of us, our linguistic conventions and inferential practices. The paper challenges logical realists to provide a non-intuition based epistemology, one which would be compatible with the empiricist and naturalist convictions motivating much recent anti-realist philosophy of mathematics.

According to an influential view, when it comes to representing reality, some words are better suited for the job than others. This is elitism. There is reason to believe that the set of the best, or elite, words should not be redundant or arbitrary. However, we are often forced to choose between these two theoretical vices, especially in cases involving theories that seem to be mere notational variants. This is the riddle of redundancy: both redundancy and arbitrariness are vicious, but (...) there are cases in which one must be picked. Logical realists admit that there are some logical constants among the elite words. This leads to awkward questions, such as which among conjunction and disjunction is elite. In this paper, I show how the riddle of redundancy arises for logical realists, and offer a solution. This approach requires us to change how we represent negation. Instead of using some particular symbol, we represent negation by flipping formulae over the horizontal axis. (shrink)

Logical realism is a view about the metaphysical status of logic. Common to most if not all the views captured by the label ‘logical realism’ is that logical facts are mind- and language-independent. But that does not tell us anything about the nature of logical facts or about our epistemic access to them. The goal of this paper is to outline and systematize the different ways that logical realism could be entertained and (...) to examine some of the challenges that these views face. It will be suggested that logical realism is best understood as a metaphysical view about the logical structure of the world, but this raises an important question: does logical realism collapse into standard metaphysical realism? It will be argued that this result can be accommodated, even if it cannot be altogether avoided. (shrink)

Philosophers of science often assume that logically equivalent theories are theoretically equivalent. I argue that two theses, anti-exceptionalism about logic (which says, roughly, that logic is not a priori, that it is revisable, and that it is not special or set apart from other human inquiry) and logical realism (which says, roughly, that differences in logic reflect genuine metaphysical differences in the world), make trouble for both this commitment and the closely related commitment to theories being closed under (...) logical consequence. I provide three arguments. The first two show that anti-exceptionalism about logic provides an epistemic challenge to both the closure and the equivalence claims; the third shows that logical realism provides a metaphysical challenge to both the closure and the equivalence claims. Along the way, I show that there are important methodological upshots for metaphysicians and philosophers of logic. In particular, there are lessons to be drawn about certain conceptions of naturalism as constraining the possibilities for metaphysics and the philosophy of logic. (shrink)

One of the most interesting programs in the foundations of quantum mechanics is the realist quantum logic approach associated with Putnam, Bub, Demopoulos and Friedman (and which is the focus of my own research.) I believe that realist quantum logic is our best hope for making sense of quantum mechanics, but I have come to suspect that the usual version may not be the correct one. In this paper, I would like to say why and to propose an alternative.

The book contains the first systematic study of the ontology and metaphysics of Gustav Bergmann, tracing their development from early (1940s) criticisms of Carnap's semantical theories in Introduction to Semantics, to their culmination in his 1992 New Foundations of Ontology. This involves a detailed study of the implicit metaphysical doctrines in Carnap's important, but long neglected, 1942 book and their connection to his influential views on reference, truth and modality, (including, contrary to current opinion, Carnap's initiating the development of predicate (...) modal logic) that culminated in Meaning and Necessity. In dealing with various fundamental issues in ontology and metaphysics, the book discusses relevant views of major philosophers, such as Russell, Moore, Bradley, Wittgenstein, Meinong, Brentano, Husserl, Broad, McTaggart, and Quine, and of contemporary and recent figures, including D. M. Armstrong, D. Lewis, S. Kripke, J. Searle, W. Sellars, D. Davidson, J. J. C. Smart, and H. Feigl. Building on the critical studies of Bergmann, Carnap and such other philosophers, the author argues for a form of Logical Realism derived from important, but long misunderstood and ignored, aspects of Russell's theories of descriptions, reference and truth. (shrink)

Logical realism is the metaphysical view asserting that the facts of logic exist and are mind-and-language independent. McSweeney argues that if logical realism is true, we encounter a dilemma. Either we cannot determine which of the two logically equivalent theories holds a fundamental status, or neither theory can be considered fundamental. These two conclusions together constitute what is known as the _Unfamiliarity Dilemma_, which poses significant challenges to our understanding of the epistemological and metaphysical features of (...) logic. In this article, I present two strategies to address McSweeney’s dilemma. If these arguments prove effective, they would demonstrate that our knowledge of logic is not susceptible to the skeptical concerns raised by McSweeney’s hypothesis. (shrink)

The paper sets out a version of a correspondence theory of truth that deals with a number of problems such theories traditionally face, problems associated with the names of Bradley, Meinong, Camap, Russell, Wittgenstein and Moore and that arise in connection with attempts to analyze facts of various logical forms. The line of argument employs a somewhat novel application of Russell's theory of definite descriptions. In developing a form of "logical realism" the paper takes up various ontological (...) issues regarding classes, causal laws, modality, predication, negation and relations. It does so in connection with critical discussions of alternative views recently proposed by Armstrong, Bergmann, Lewis and Putnam. (shrink)

Applying the rules and systems of mathematics and logic to instance ontology, this work argues for the validity and problem-solving capacities of instance ontology, and associates it with a version of the realist position which is named by the author as moderate realism.

Anti-realistic conceptions of truth and falsity are usually epistemic or inferentialist. Truth is regarded as knowability, or provability, or warranted assertability, and the falsity of a statement or formula is identified with the truth of its negation. In this paper, a non-inferentialist but nevertheless anti-realistic conception of logical truth and falsity is developed. According to this conception, a formula (or a declarative sentence) A is logically true if and only if no matter what is told about what is told (...) about the truth or falsity of atomic sentences, A always receives the top-element of a certain partial order on non-ontic semantic values as its value. The ordering in question is a told-true order. Analogously, a formula A is logically false just in case no matter what is told about what is told about the truth or falsity of atomic sentences, A always receives the top-element of a certain told-false order as its value. Here, truth and falsity are pari passu , and it is the treatment of truth and falsity as independent of each other that leads to an informational interpretation of these notions in terms of a certain kind of higher-level information. (shrink)

Anti-realism is a doctrine about logic, language, and meaning that is based on the work of Wittgenstein and Frege. In this book, Professor Tennant clarifies and develops Dummett's arguments for anti-realism and ultimately advocates a radical reform of our logical practices.

The paper discusses which modal principles should hold for a truth operator answering to the truth theory of internal realism. It turns out that the logic of truth in internal realism is isomorphic to the modal system S4.

The relation between logic and knowledge has been at the heart of a lively debate since the 1960s. On the one hand, the epistemic approaches based their formal arguments in the mathematics of Brouwer and intuitionistic logic. Following Michael Dummett, they started to call themselves `antirealists'. Others persisted with the formal background of the Frege-Tarski tradition, where Cantorian set theory is linked via model theory to classical logic. Jaakko Hintikka tried to unify both traditions by means of what is now (...) known as `explicit epistemic logic'. Under this view, epistemic contents are introduced into the object language as operators yielding propositions from propositions, rather than as metalogical constraints on the notion of inference. The Realism-Antirealism debate has thus had three players: classical logicians, intuitionists and explicit epistemic logicians. The editors of the present volume believe that in the age of Alternative Logics, where manifold developments in logic happen at a breathtaking pace, this debate should be revisited. Contributors to this volume happily took on this challenge and responded with new approaches to the debate from both the explicit and the implicit epistemic point of view. (shrink)

This chapter contains sections titled: I II.

-- James Der Derian, University of Massachusetts.

A chief aim of this paper is to provide common ground for discussion of outstanding issues between defenders of classical logic and contemporary advocates of intuitionistic logic. In this spirit, I draw upon (and reconstruct) here the relationship between dialogue and evidence as emphasized in German constructivist authors. My approach depends upon developments in the methodology of empirical linguistics. As a preliminary to saying how one might decide between these two versions of logic (this issue is most closely approached in (...) Section V. discussing the constructivist approach), it is well worth the effort to look closely at how logic is (or might be) learned and at questions concerning logic in translation, i.e., the question of how we might detect the variety of logic actually employed in a given speech community. (shrink)

I undertake to explain how the well known laws of formal logic – Barbara Syllogism, modus ponens, etc. – relate to experience by developing Edmund Husserl's critique ofFormalism and Psychologism in logical theory and then briefly explaining his positive views of the laws of logic. His view rests upon his understanding of the proposition as a complex, intentional property. The laws of formal logic are, on his view (and mine), statements about the truth values of propositions as determined by (...) their formal character and relationships alone. The laws thus understood explain how algorithms set up to mirror them can accomplish what they do to advance knowledge, even though they operate purely mechanically. Further, they explain the proper sense in which formal laws "govern," and may guide, processes of actual thinking. Husserl's theory is a realist theory in the sense that, on his interpretation, the laws of pure or formal logic hold true regardless of what any individual, culture or species may or may not think, or even if no thinking ever occurs. (shrink)

In this rejoinder to the critical comments elicited by my essay “Existential Hypotheses,” I propose to deal first with the challenge coming from the avowedly different philosophical outlook of Professor Churchman. My other critics, Professors Frank, Hempel, Nagel and Ramsperger, on the whole, share my basic conception of the tasks of philosophy of science and epistemology, even if they dissent in one important respect or another from the special solution I suggested. But since I discern even in Professor Nagel's remarks (...) a pragmatist or instrumentalist strain akin to the major contentions of Professor Churchman, it will be well to begin with a defense and further clarification of my underlying point of view. Only after this restatement of my platform will I undertake to defend semantic realism against the specific criticisms advanced by the last four authors. (shrink)

The problematic features of Quine's set theories NF and ML are a result of his replacing the higher-order predicate logic of type theory by a first-order logic of membership, and can be resolved by returning to a second-order logic of predication with nominalized predicates as abstract singular terms. We adopt a modified Fregean position called conceptual realism in which the concepts (unsaturated cognitive structures) that predicates stand for are distinguished from the extensions (or intensions) that their nominalizations denote as (...) singular terms. We argue against Quine's view that predicate quantifiers can be given a referential interpretation only if the entities predicates stand for on such an interpretation are the same as the classes (assuming extensionality) that nominalized predicates denote as singular terms. Quine's alternative of giving predicate quantifiers only a substitutional interpretation is compared with a constructive version of conceptual realism, which with a logic of nominalized predicates is compared with Quine's description of conceptualism as a ramified theory of classes. We argue against Quine's implicit assumption that conceptualism cannot account for impredicative concept-formation and compare holistic conceptual realism with Quine's class Platonism. (shrink)

Logical empiricism is commonly seen as a counter-position to scientific realism. In the present paper it is shown that there indeed existed a realist faction within the logical empiricist movement. In particular, I shall point out that at least four types of realistic arguments can be distinguished within this faction: Reichenbach’s ‘probabilistic argument,’ Feigl’s ‘pragmatic argument,’ Hempel’s ‘indispensability argument,’ and Kaila’s ‘invariantist argument.’ All these variations of arguments are intended to prevent the logical empiricist agenda from (...) the shortcomings of radical positivism, instrumentalism, and other forms of scientific antirealism. On the whole, it will be seen that logical empiricism and scientific realism are essentially compatible with each other. Especially Kaila’s invariantist approach to science (and nature) comes quite close to what nowadays is discussed under the label ‘structural realism.’ This, in turn, necessitates a fundamental reevaluation of Kaila’s role in the logical empiricist movement in particular and in twentieth-century philosophy of science in general. (shrink)

_Realism and the Aim of Science_ is one of the three volumes of Karl Popper’s _Postscript_ to the Logic of scientific Discovery. The _Postscript_ is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. _Realism and the Aim of Science_ is the first volume of the _Postcript_. Popper here formulates and explains his non-justificationist theory of knowledge: science aims at true explanatory theories, yet it can never prove, (...) or justify, any theory to be true, not even if is a true theory. Science must continue to question and criticise all its theories, even those that happen to be true. _Realism and the Aim of Science_ presents Popper’s mature statement on scientific knowledge and offers important insights into his thinking on problems of method within science. (shrink)

According to the realist interpretation, measurement commits us not just to the logically independent existence of things in space and time, but also to the existence of quantitatively structured properties and relations, and to the existence of real numbers, understood as relations of ratio between specific levels of such attributes. Measurement is defined as the estimation of numerical relations (or ratios) between magnitudes of a quantitative attribute and a unit. The history of scientific measurement, from antiquity to the present may (...) be interpreted as revealing a progressive deepening in the understanding of this position. First, the concept of ratio was broadened to include ratios between incommensurable magnitudes; second, the concept of a quantitative attribute was broadened to include non-extensive quantities; third, quantitative structure and its relations to ratios and real numbers were elaborated; and finally, the issue of empirically distinguishing between quantitative and non-quantitative structures was addressed. This interpretation of measurement understands it in a way that is continuous with scientific investigation in general, i.e., as an attempt to discover independently existing facts. (shrink)

D. W. Mertz provides a "new" competitor in the universals debate by reviving, developing, and defending the medieval doctrine of Moderate Realism. This book is a substantial contribution to ontology and logic, combining interesting new arguments for polyadic relations and unit attributes, careful and thorough historical studies, and a logic that could solve many old problems.

Realism and the Aim of Science is one of the three volumes of Karl Popper’s Postscript to the Logic of scientific Discovery. The Postscript is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. Realism and the Aim of Science is the first volume of the Postcript . Popper here formulates and explains his non-justificationist theory of knowledge: science aims at true explanatory theories, yet it (...) can never prove, or justify, any theory to be true, not even if is a true theory. Science must continue to question and criticise all its theories, even those that happen to be true. Realism and the Aim of Science presents Popper’s mature statement on scientific knowledge and offers important insights into his thinking on problems of method within science. (shrink)

In the Logic of Being: Realism, Truth, and Time, the influential philosopher Paul M. Livingston explores and illuminates truth, time, and their relationship by employing methods from both Continental and analytic philosophy.

Critical realism claims to bring a significant improvement to social science, especially in comparison with empiricist and interpretive approaches. So far, however, it has fallen short of the high expectations it raises. Critical realist arguments are convincing on the philosophical or meta-theoretical level but the contributions of critical realism to social science in terms of research activities at the field level are less clear. Nonetheless, there is no way back. Moving forward requires that the practice of doing social (...) scientific research be no longer perceived as limited to the justification of specific knowledge claims but must be seen as an integral part of the cycle of scientific discovery. (shrink)

Instance ontology, or particularism - the doctrine that asserts the individuality of properties and relations - has been a persistent topic in Western philosophy, discussed in works by Plato and Aristotle, by Muslim and Christian scholastics, and by philosophers of both realist and nominalist positions. This book by D.W. Mertz is the first sustained analysis that applies the rules and systems of mathematics and logic to instance ontology in order to argue for its validity and for its problem-solving capacities and (...) to associate it with a version of the realist position that Mertz calls "moderate realism.". (shrink)

Scientific realism is the view that the theoretical entities of science exist. Atoms, forces, electromagnetic fields, and so on, are not merely instruments for organizing observational data but are real and causally effective. This view seems to be hardly compatible with the logical empiricist agenda: As common wisdom has it, logical empiricism is mainly characterized by a strong verification criterion of meaning, i.e., by the project of defining the meaning of theoretical terms by virtue of the meaning (...) of purely observational terms. However, it has been largely ignored by the historians of logical empiricism that there indeed existed a realist faction within the logical empiricist movement. (shrink)

Husserl’s conception of ideal objects convinced some of his early disciples that he was presenting a new form of realism. This impression arises, in my view, from a twofold misunderstanding. First, there was a misunderstanding of the limits of the phenomenological claims of Logical Investigations and, second, an erroneous belief that ideal objects are interpreted in a realist fashion therein. The ultimate source of the first phenomenological schism is not, therefore, so much a reaction to an alleged sudden (...) change in Husserl’s position, but rather a misunderstanding of the concept of ideality presented in Logical Investigations. Further, an alleged “compatibility” between the realist conception of ideality and the Husserlian conception is to be found in one of the ways that Husserl addresses the problem of constitution. However, the Spanish philosopher Antonio Millán-Puelles has shown that the use of terms such as “constitutive activity” or “genesis”—in a realist metaphysics, to designate the arising of ideal objects—should not be interpreted in a psychologistic way, as though these objects remained absorbed by the reality of the mental processes they are made present by. (shrink)

The framework of conceptual realism provides a logically ideal language within which to reconstruct the medieval terminist logic of the 14th century. The terminist notion of a concept, which shifted from Ockham's early view of a concept as an intentional object to his later view of a concept as a mental act , is reconstructed in this framework in terms of the idea of concepts as unsaturated cognitive structures. Intentional objects are not rejected but are reconstructed as the objectified (...) intensional contents of concepts. Their reconstruction as intensional objects is an essential part of the theory of predication of conceptual realism. It is by means of this theory that we are able to explain how the identity theory of the copula, which was basic to terminist logic, applies to categorical propositions. Reference in conceptual realism is not the same as supposition in terminist logic. Nevertheless, the various "modes" of personal supposition of terminist logic can be explained and justified in terms of this conceptualist theory of reference. (shrink)

I defend logical realism. I begin by motivating the realist approach by underlining the difficulties for its main rival: inferentialism. I then focus on AND and OR, and delineate a realist view of these two logical constants. The realist view is developed in terms of Alexander’s Principleshowing that AND and OR have distinctive determining roles. After that, I say what logic is not. We should not take logic to be essentially about the mind, or language, or exclusively (...) about an abstract realm, or about reasoning, truth, truth-tables, truth-functions, topic-neutrality or form. Lastly, I turn to consider NEGATION and argue that we cannot escape negative facts, and facts conjoining and disjoining negative facts with positive facts. I then give NEGATION a distinctive role, one that contrasts with AND and OR. I reflect on the notion of logic in the coda. (shrink)