This unique book provides a gentle introduction to an increasingly important type of formal logic called CLAUSAL FORM LOGIC (CFL). Having evolved out of human reasoning, CFL represents the ideal to which all computer-based systems must approximate. Most present day computational logic systems are based on it, including the well-know artificial intelligence language PROLOG.

We investigate a construction schema for first-order logical systems, called “form logic”. Form logic allows us to overcome the dualistic commitment of predicate logic to individual constants and predicates. Dualism is replaced by a pluralism of terms of different “logical forms”. Individual form-logical systems are generated by the determination of a range of logical forms and of the formbased syntax rules for combining terms into formulas. We develop a generic syntax and semantics for such (...) systems and provide a completeness proof for them. To illustrate the idea of form logic, and the possibilities it facilitates, we discuss three particular systems, one of which is the form-logical reconstruction of standard first-order predicate logic. (shrink)

Hence, this book's provocative claim: today's so-called logical empiricism owes much more to Kant's notion of science than to Hume's.

The Joint International Conference on Logic Programming, sponsored by the Association for Logic Programming, is a major forum for presentations of research, applications, and implementations in this important area of computer science. Logic programming is one of the most promising steps toward declarative programming and forms the theoretical basis of the programming language Prolog and its various extensions. Logic programming is also fundamental to work in artificial intelligence, where it has been used for nonmonotonic and commonsense (...) reasoning, expert systems implementation, deductive databases, and applications such as computer-aided manufacturing. Krzysztof R. Apt is project leader at the Centre for Mathematics and Computer Science in Amsterdam and part-time Professor in Computer Science at the University of Amsterdam. Topics covered: Theory Foundations. Programming Languages. Implementation. Programming Methodologies and Tools. Applications. Deductive Databases. Artificial Intelligence. Parallelism. (shrink)

_Questions of Form _was first published in 1989. Minnesota Archive Editions uses digital technology to make long-unavailable books once again accessible, and are published unaltered from the original University of Minnesota Press editions. In _Questions on Form_, Joelle Proust traces the concept of the analytic proposition from Kant's development of the notion down to its place in the work of Rudolf Carnap, a founder of logical empiricism and a key figure in contemporary analytic philosophy. Using a method known in (...) France as _topique comparative_,she provides a rigorous exposition of analyticity, situating it within four major philosophical systems—those of Kant, Bolzano, Frege, and Carnap—and clearly delineating its development from one system to the next. Proust takes as her point of departure Kant's distinction between analytic and synthetic judgments. Though she makes clear that Kant drew on Locke, Hume, and Leibniz, she argues that his notion of analyticity was innovative, not simply an elaboration of something already found in their work. She shows that the analytic proposition unexpectedly came to play an important part in efforts to convert problems considered "transcendental" into questions of belonging to formal logic. Ultimately, her comparison of their systems reveals that the concept of the analytic, however specific its rile in each, remains linked to a foundationalist strategy—in effect, to the transcendentalist questions Kant used when he reinterpreted the findings of his empiricist predecessors. Hence, this book's provocative claim: today's so-called logical empiricism owes much more to Kant's notion of science than to Hume's. (shrink)

Theories of adverbial modification can be roughly distinguished into two sorts. One kind of theory takes logical form to follow surface grammatical form. Adverbs are treated as unanalyzable logical operators that turn a predicate or sentence into a different predicate or sentence respectively. And new rules of logic are stated for these operators. -/- A different kind of theory does not suppose that logical form must parallel surface grammatical form. It allows that logical form (...) may have more to do with deeper structures that might be studied in transformational grammar. Adverbs are treated as surface forms of the underlying predicates represented by corresponding adjectives and verbs. 'Slowly' is derived from 'slow'; 'intentionally' from 'intentional' or 'intend'; etc. And new rules of logic are avoided where they can be. -/- In this paper I attempt to state some of the advantages of the second sort of theory. My procedure will be this. First, I will try to say in outline what theories of logical form are. Then I will state five principles for evaluating such theories. Next, I will sketch the sorts of analyses acceptance of principles (1)-(5) leads to. In particular I will talk about adverbial phrases (e.g. locatives) that are best analyzed in terms of implicit references to events, relative modifiers (like 'large') which relate something to a comparison class, and 'that' clauses taken as names of propositions. By appealing to principles (1)-(5) I will defend these analyses against certain others, one that appeals to many logical operators, a second that treats all sentences as names of propositions, and a third that sees implicit reference to possible worlds in the language being analyzed. Finally, I will offer a pragmatic defense of my approach in terms of principles (1)-(5) as against a different approach that appeals to possible world semantics. (shrink)

Seventeen specially written essays by eminent philosophers and linguists appear for the first time in this anthology, all with the central theme of logical form -- a fundamental issue in analytic philosophy and linguistic theory. Logical Form and Language brings together exciting new contributions from diverse points of view, which illuminate the lively current debate about this topic.

The standard view of logical form is that logical forms are synthetic structures which are the forms of sentences and of other linguistic entities. This is often associated with a more general linguistic view of logic which is articulated in different ways by various authors. This paper contains a critical discussion of such linguistic approaches to logical form, with special emphasis on Quine’s formulation of a logical grammar in Philosophy of Logic. An account of logical forms (...) as higher-order properties, which essentially builds on Frege’s analysis of quantification as higher-order predication, is suggested at the end. (shrink)

Conventionalism about mathematics has much in common with two other views: fictionalism and the multiverse view (aka plenitudinous platonism). The three views may differ over the existence of mathematical objects, but they agree in rejecting a certain kind of objectivity claim about mathematics, advocating instead an extreme pluralism. The early parts of the paper will try to elucidate this anti‐objectivist position, and question whether conventionalism really offers a third form of it distinct from fictionalism and the multiverse view. The (...) paper then turns to anti‐objectivism about logic, and suggests that here too conventionalism offers no distinct alternative, and that there are limits on the extent of pluralism/anti‐objectivism. It also argues that these limits can't be used to argue for more extensive objectivity within mathematics, and also that they do allow for more limited pluralism within logic, e.g. as regards resolution of semantic and property‐theoretic paradoxes. (shrink)

Logical Forms examines the formal languages of classical first order logic and modal logic, and some alternatives and in each case takes as the central question: how can natural language best be formalized in this formal language? The approach involves close encounters with issues in the philosophy of logic and the philosophy of logic and the philosophy of language.

Logical Form, Probability Interpretations, and the Inductive/Deductive Distinction.

Antoine Arnauld and Pierre Nicole were philosophers and theologians associated with Port-Royal Abbey, a centre of the Catholic Jansenist movement in seventeenth-century France. Their enormously influential Logic or the Art of Thinking, which went through five editions in their lifetimes, treats topics in logic, language, theory of knowledge and metaphysics, and also articulates the response of 'heretical' Jansenist Catholicism to orthodox Catholic and Protestant views on grace, free will and the sacraments. In attempting to combine the categorical theory (...) of the proposition with a Cartesian account of knowledge, their Logic represents the classical view of judgment which inspired the modern transformation in logic and semantic theory by Frege, Russell, Wittgenstein and recent philosophers. This edition presents a new translation of the text, together with a historical introduction and suggestions for further reading. (shrink)

Proofs and Refutations is essential reading for all those interested in the methodology, the philosophy and the history of mathematics. Much of the book takes the form of a discussion between a teacher and his students. They propose various solutions to some mathematical problems and investigate the strengths and weaknesses of these solutions. Their discussion raises some philosophical problems and some problems about the nature of mathematical discovery or creativity. Imre Lakatos is concerned throughout to combat the classical picture (...) of mathematical development as a steady accumulation of established truths. He shows that mathematics grows instead through a richer, more dramatic process of the successive improvement of creative hypotheses by attempts to 'prove' them and by criticism of these attempts: the logic of proofs and refutations. (shrink)

First order logic does not distinguish between different forms of universal generalization; in this paper I argue that lawlike and accidental generalizations (broadly construed) have a different logical form, and that this distinction is syntactically marked in English. I then consider the relevance of this broader conception of lawlikeness to the philosophy of science.

Two arguments favoring propositionalist accounts of attitude sentences are being revisited: the Church-Langford translation argument and Thomason's argument against quotational theories of indirect discourse. None of them proves to be decisive, thus leaving the option of searching for a developed quotational alternative. Such an alternative is found in an interpreted logical form theory of attitude ascription. The theory differentiates elegantly among different attitudes but it fails to account for logical dependencies among them. It is argued, however, that the concept (...) of logical consequence does not well apply to dependencies among belief sentences and that the requirement to account for logical relations among such sentences should be relaxed. (shrink)

Logical form has always been a prime concern for philosophers belonging to the analytic tradition. For at least one century, the study of logical form has been widely adopted as a method of investigation, relying on its capacity to reveal the structure of thoughts or the constitution of facts. This book focuses on the very idea of logical form, which is directly relevant to any principled reflection on that method. Its central thesis is that there is no (...) such thing as a correct answer to the question of what is logical form: two significantly different notions of logical form are needed to fulfil two major theoretical roles that pertain respectively to logic and to semantics. This thesis has a negative and a positive side. The negative side is that a deeply rooted presumption about logical form turns out to be overly optimistic: there is no unique notion of logical form that can play both roles. The positive side is that the distinction between two notions of logical form, once properly spelled out, sheds light on some fundamental issues concerning the relation between logic and language. (shrink)

Branching-time temporal logics have proved to be an extraordinarily successful tool in the formal specification and verification of distributed systems. Much of their success stems from the tractability of the model checking problem for the branching time logic CTL, which has made it possible to implement tools that allow designers to automatically verify that systems satisfy requirements expressed in CTL. Recently, CTL was generalised by Alur, Henzinger, and Kupferman in a logic known as Alternating-time Temporal Logic (ATL). (...) The key insight in ATL is that the path quantifiers of CTL could be replaced by cooperation modalities, of the form , where is a set of agents. The intended interpretation of an ATL formula is that the agents can cooperate to ensure that holds (equivalently, that have a winning strategy for ). In this paper, we extend ATL with knowledge modalities, of the kind made popular in the work of Fagin, Halpern, Moses, Vardi and colleagues. Combining these knowledge modalities with ATL, it becomes possible to express such properties as group can cooperate to bring about iff it is common knowledge in that . The resulting logic — Alternating-time Temporal Epistemic Logic (ATEL) — shares the tractability of model checking with its ATL parent, and is a succinct and expressive language for reasoning about game-like multiagent systems. (shrink)

The word ‘logic’ has many senses. Here we will understand it as meaning an account of what follows from what and why. With contemporary methodology, logic in this sense – though it may not always have been thought of in this way – is a branch of applied mathematics. This has various implications for how one understands a number of issues concerning validity. In this paper I will explain this perspective of logic, and explore some of its (...) consequences with respect to the notion of logical form. (shrink)

Paraconsistent Weak Kleene logic is the 3-valued logic with two designated values defined through the weak Kleene tables. This paper is a first attempt to investigate PWK within the perspective and methods of abstract algebraic logic. We give a Hilbert-style system for PWK and prove a normal form theorem. We examine some algebraic structures for PWK, called involutive bisemilattices, showing that they are distributive as bisemilattices and that they form a variety, \, generated by the (...) 3-element algebra WK; we also prove that every involutive bisemilattice is representable as the Płonka sum over a direct system of Boolean algebras. We then study PWK from the viewpoint of AAL. We show that \ is not the equivalent algebraic semantics of any algebraisable logic and that PWK is neither protoalgebraic nor selfextensional, not assertional, but it is truth-equational. We fully characterise the deductive filters of PWK on members of \ and the reduced matrix models of PWK. Finally, we investigate PWK with the methods of second-order AAL—we describe the class \ of PWK-algebras, algebra reducts of basic full generalised matrix models of PWK, showing that they coincide with the quasivariety generated by WK—which differs from \—and explicitly providing a quasiequational basis for it. (shrink)

The central thesis of the article is that there are two quite distinct concepts of logical form. Theories of logical form employing one of these concepts are different both in method of justification and in philosophical and psychological implications from theories employing the other concept.

This book is a consideration of Hegel’s view on logic and basic logical concepts such as truth, form, validity, and contradiction, and aims to assess this view’s relevance for contemporary philosophical logic. The literature on Hegel’s logic is fairly rich. The attention to contemporary philosophical logic places the present research closer to those works interested in the link between Hegel’s thought and analytical philosophy, Koch 2014, Brandom 2014, 1-15, Pippin 2016, Moyar 2017, Quante & Mooren (...) 2018 among others). In this context, one particularity of this book consists in focusing on something that has been generally underrated in the literature: the idea that, for Hegel as well as for Aristotle and many other authors, logic is the study of the forms of truth, i.e. the forms that our thought can assume in searching for truth. In this light, Hegel’s thinking about logic is a fundamental reference point for anyone interested in a philosophical foundation of logic. (shrink)

This paper reflects on the limits of logical form set by a novel criterion of logicality proposed in (Bonnay and Speitel, 2021). The interest stems from the fact that the delineation of logical terms according to the criterion exceeds the boundaries of standard first-order logic. Among ‘novel’ logical terms is the quantifier “there are infinitely many”. Since the structure of the natural numbers is categorically characterisable in a language including this quantifier we ask: does this imply that arithmetical (...) forms have been reduced to logical forms? And, in general, what other conditions need to be satisfied for a form to qualify as “fully logical”? We survey answers to these questions. (shrink)

In recent years, the logic of questions and dependencies has been investigated in the closely related frameworks of inquisitive logic and dependence logic. These investigations have assumed classical logic as the background logic of statements, and added formulas expressing questions and dependencies to this classical core. In this paper, we broaden the scope of these investigations by studying questions and dependency in the context of intuitionistic logic. We propose an intuitionistic team semantics, where teams (...) are embedded within intuitionistic Kripke models. The associated logic is a conservative extension of intuitionistic logic with questions and dependence formulas. We establish a number of results about this logic, including a normal form result, a completeness result, and translations to classical inquisitive logic and modal dependence logic. (shrink)

Logical Forms explains both the detailed problems involved in finding logical forms and also the theoretical underpinnings of philosophical logic. In this revised edition, exercises are integrated throughout the book. The result is a genuinely interactive introduction which engages the reader in developing the argument. Each chapter concludes with updated notes to guide further reading.

Information-theoretic approaches to formal logic analyse the "common intuitive" concept of propositional implication (or argumental validity) in terms of information content of propositions and sets of propositions: one given proposition implies a second if the former contains all of the information contained by the latter; an argument is valid if the conclusion contains no information beyond that of the premise-set. This paper locates information-theoretic approaches historically, philosophically and pragmatically. Advantages and disadvantages are identified by examining such approaches in themselves (...) and by contrasting them with standard transformation-theoretic approaches. Transformation-theoretic approaches analyse validity (and thus implication) in terms of transformations that map one argument onto another: a given argument is valid if no transformation carries it onto an argument with all true premises and false conclusion. Model-theoretic, set-theoretic, and substitution-theoretic approaches, which dominate current literature, can be construed as transformation-theoretic, as can the so-called possible-worlds approaches. Ontic and epistemic presuppositions of both types of approaches are considered. Attention is given to the question of whether our historically cumulative experience applying logic is better explained from a purely information-theoretic perspective or from a purely transformation-theoretic perspective or whether apparent conflicts between the two types of approaches need to be reconciled in order to forge a new type of approach that recognizes their basic complementarity. (shrink)

Natural languages are riddled with context-sensitivity. One and the same string of words can express many different meanings on occasion of use, and yet we understand one another effortlessly, on the fly. How do we do so? What fixes the meaning of context-sensitive expressions, and how are we able to recover the meaning so effortlessly? -/- This book offers a novel response: we can do so because we draw on a broad array of subtle linguistic conventions that determine the interpretation (...) of context-sensitive items. Contrary to the dominant tradition, which maintains that the meaning of context-sensitive language is underspecified by grammar and that interpretation relies on non-linguistic cues and speakers' intentions, this book argues that meaning is determined entirely by discourse conventions, rules of language that have largely been missed and the effects of which have been mistaken for extra-linguistic effects of an utterance situation on meaning. The linguistic account of context developed here sheds new light on the nature of linguistic content and the interaction between content and context. At the same time, it provides a novel model of context that should constrain and help evaluate debates across many subfields of philosophy where appeal to context has been common, often leading to surprising conclusions such as epistemology, ethics, value theory, metaphysics, metaethics, and logic. (shrink)

This is a formal and systematic study of the logical foundations of speech act theory. The study of speech acts has been a flourishing branch of the philosophy of language and linguistics over the last two decades, and John Searle has of course himself made some of the most notable contributions to that study in the sequence of books Speech Acts, Expression and Meaning and Intentionality. In collaboration with Daniel Vanderveken he now presents the first formalised logic of a (...) general theory of speech acts, dealing with such things as the nature of an illocutionary force, the logical form of its components, and the conditions of success of elementary illocutionary acts. The central chapters present a systematic exposition of the axioms and general laws of illocutionary logic. (shrink)

The present monograph is a slightly revised version of my Habilitations schrift Proof-theoretic Aspects of Intensional and Non-Classical Logics, successfully defended at Leipzig University, November 1997. It collects work on proof systems for modal and constructive logics I have done over the last few years. The main concern is display logic, a certain refinement of Gentzen's sequent calculus developed by Nuel D. Belnap. This book is far from offering a comprehensive presentation of generalized sequent systems for modal logics broadly (...) conceived. The proof-theory of non-classical logics is a rapidly developing field, and even the generalizations of the ordinary notion of sequent listed in Chapter 1 can hardly be presented in great detail within a single volume. In addition to further investigating the various approaches toward generalized Gentzen systems, it is important to compare them and to discuss their relative advantages and disadvantages. An initial attempt at bringing together work on different kinds of proof systems for modal logics has been made in [188]. Another step in the same direction is [196]. Since Chapter 1 contains introductory considerations and, moreover, every remaining chapter begins with some surveying or summarizing remarks, in this preface I shall only emphasize a relation to philosophy that is important to me, register the sources of papers that have entered this book in some form or another, and acknowledge advice and support. (shrink)

This work contains Peter Long's important essay, Logic, Form and Grammar , which resolves many difficulties for the logical form of an argument where the reasoning is hypothetical. Also included are two essays on classical problems in philosophical logic, relating to logical form and formal relations.

This book, one of the handful of truly pathbreaking works in twentieth-century philosophical theology, presents Hartshorne's persuasive rehabilitation of Anselm's Ontological Argument, recast in neoclassical form as "the Modal Proof.".

In “The logic of deep disagreements” (Informal Logic, 1985), Robert Fogelin claimed that there is a kind of disagreement – deep disagreement – which is, by its very nature, impervious to rational resolution. He further claimed that these two views are attributable to Wittgenstein. Following an exposition and discussion of that claim, we review and draw some lessons from existing responses in the literature to Fogelin’s claims. In the final two sections (6 and 7) we explore the role (...) reason can, and sometimes does, play in the resolution of deep disagreements. In doing this we discuss a series of cases, mainly drawn from Wittgenstein, which we take to illustrate the resolution of deep disagreements through the use of what we call “rational persuasion.” We conclude that, while the role of argumentation in “normal” versus “deep” disagreements is characteristically different, it plays a crucial role in the resolution of both. (shrink)

Pierre de Fermat is known as the inventor of modern number theory. He invented–improved many methods useful in this discipline. Fermat often claimed to have proved his most difficult theorems thanks to a method of his own invention: the infinite descent. He wrote of numerous applications of this procedure. Unfortunately, he left only one almost complete demonstration and an outline of another demonstration. The outline concerns the theorem that every prime number of the form 4n + 1 is the (...) sum of two squares. In this paper, we analyse a recent proof of this theorem. It is interesting because: it follows all the elements of which Fermat wrote in his outline; it represents a good introduction to all logical nuances and mathematical variants concerning this method of which Fermat spoke. The assertions by Fermat will also be framed inside their historical context. Therefore, the aims of this paper are related to the history of mathematics and to the logic of proof-methods. (shrink)

Al-Abharī’s Isagoge is an introductory primer in logic which has received numerous commentaries, each geared towards students of various levels of familiarity with this instrumental science. Al-Fanārī’s advanced commentary on the Isagoge, called al-Fawāʾid al-Fanāriyya, has confounded students of logic for centuries due to its terse and dense style as well as the presumption that the reader knows well the science of disputation along with the subtle interpretive disagreements discussed in other texts and commentaries. Sājaqlīzādah’s primer on disputation (...) entitled al-Waladiyya, written nearly 300 years after al-Fanārī’s commentary, provides useful examples of the possible claims, objections, and defenses available to one making scholarly claims in the form of definitions, classifications, and propositional assents or syllogistic reasoning. In this article, I explore several instances of al-Fanārī’s use of the terms and methods of disputation in order to defend definitions or classifications found al-Abharī’s Isagoge. I aim to identify the specific disputational moves used by al-Fanārī, drawing from those described by Sājaqlīzādah. In doing so, I demonstrate that this important advanced commentary on a popular logic primer is best understood through the lens of disputation. I also argue that Sājaqlīzādah’s suggested methods of making claims, objections, and defenses can be transposed in whole or in part from one category of claim—definitions, classifications, assents—to another, indicating a greater complexity of disputational possibilities than his introductory handbook provides. (shrink)

This paper articulates and defends a conception of logical form as semantic form revealed by a compositional meaning theory. On this conception, the logical form of a sentence is determined by the semantic types of its primitive terms and their mode of combination as it relates to determining under what conditions it is true. We develop this idea in the framework of truth-theoretic semantics. We argue that the semantic form of a declarative sentence in a language (...) L is revealed by a (canonical) proof of its T- sentence in an interpretive truth theory for L. We give a precise characterization of sameness of logical form between any two declarative sentences in any two languages in terms of the notion of corresponding proofs in interpretive truth theories for the languages. We illustrate the utility of this approach with a number of examples. We then extend the characterization to non-declaratives in a generalization of truth-theoretic semantics that appeals to fulfillment conditions, of which truth conditions are one variety. On this approach, logical forms are not reified, and the notion of sameness of logical form is treated as conceptually basic. We discuss the relation of this conception of logical form to the project of identifying logical constants, reviewing two approaches, one of which takes topic neutrality as central, the other recursion. We argue that the project of identifying logical constants for the purposes of classifying together valid arguments is largely independent of that identifying logical form of sentences, and urge an ecumenical approach to extending talk of logical constants beyond where it is currently well-grounded. (shrink)

Science studies not only material entities and phenomena, but their reflections in the minds of men, in the form of sensations, perceptions, concepts, and the like. The study of a phenomenon like language involves simultaneous examinations of material entities and the aspect of language which pertains to meaning, which takes shape as a result of man's reflection in cognition of the world around him.

Filling the need for an accessible, carefully structured introductory text in symbolic logic, Modern Logic has many features designed to improve students' comprehension of the subject, including a proof system that is the same as the award-winning computer program MacLogic, and a special appendix that shows how to use MacLogic as a teaching aid. There are graded exercises at the end of each chapter--more than 900 in all--with selected answers at the end of the book. Unlike competing texts, (...) Modern Logic gives equal weight to semantics and proof theory and explains their relationship, and develops in detail techniques for symbolizing natural language in first-order logic. After a general introduction featuring the notion of logical form, the book offers sections on classical sentential logic, monadic predicate logic, and full first-order logic with identity. A concluding section deals with extensions of and alternatives to classical logic, including modal logic, intuitionistic logic, and fuzzy logic. For students of philosophy, mathematics, computer science, or linguistics, Modern Logic provides a thorough understanding of basic concepts and a sound basis for more advanced work. (shrink)

We present probabilistic approaches to check the validity of selected connexive principles within the setting of coherence. Connexive logics emerged from the intuition that conditionals of the form If ∼A, then A, should not hold, since the conditional’s antecedent ∼A contradicts its consequent A. Our approach covers this intuition by observing that for an event A the only coherent probability assessment on the conditional event A|~A is p(A|~A)=0 . Moreover, connexive logics aim to capture the intuition that conditionals should (...) express some “connection” between the antecedent and the consequent or, in terms of inferences, validity should require some connection between the premise set and the conclusion. This intuition is covered by a number of principles, a selection of which we analyze in our contribution. We present two approaches to connexivity within coherence-based probability logic. Specifically, we analyze connections between antecedents and consequents firstly, in terms of probabilistic constraints on conditional events (in the sense of defaults, or negated defaults) and secondly, in terms of constraints on compounds of conditionals and iterated conditionals. After developing different notions of negations and notions of validity, we analyze the following connexive principles within both approaches: Aristotle’s Theses, Aristotle’s Second Thesis, Abelard’s First Principle and selected versions of Boethius’ Theses. We conclude by remarking that coherence-based probability logic offers a rich language to investigate the validity of various connexive principles. (shrink)

The knowledge norm of assertion is the subject of a lively debate on when someone is in a position to assert something. However, not much has been said about the logic that underlies such debate. In this paper, I propose a formalisation of the knowledge norm in a deontic logic that aims to be explanatory and conceptually sound. Afterwards, I investigate some problems that this formalisation makes visible. This reveals some significant limitations of the underlying logic: it (...) can neither contain Axiom 4 nor Axiom C4. Moreover, sentences of the form p and I have not asserted that p appear to licence a violation of deontic rules. (shrink)

Logic as an activity deals with the interplay or the dialectic, as one thinks, between the known and the unknown, form and content, or the formal and the intuitive. For this purpose it is useful to select from what is taken to be known a universal part which remains fixed throughout all particular instances of the interplay. The propositions in such a universal part make up the logical truths. There are alternative answers to the question: What is to (...) be required of the concepts and the propositions of this universal part? Different choices can be and have been made with regard to the kind and the degree of their universality, and the degree of precision and systematic character of their codification. These different choices lead to different conceptions of logic, such as those of William of Occam, Kant, Hegel, Frege, Brouwer, the early Wittgenstein, the later Wittgenstein, and Gödel. (shrink)

In his paper John Corcoran examines in detail many issues relating to logical form, and raises some questions about my formulations. In my response I emphasize two main distinctions that may clear up some of the issues. One is the distinction between logical forms, in the sense of logical properties of an abstract character, and logical form, in the sense in which we speak of the logical form of a sentence, or of a proposition. Another is the (...) distinction, emphasized by Boole, between primary propositions , and secondary propositions —which I illustrate through the distinction between predicate negation and sentential negation.Em seu artigo John Corcoran examina em detalhe muitas questões sobre forma lógica e levanta alguns problemas relativos à minhas formulações. Na réplica enfatizo duas distinções principais, que podem esclarecer algumas questões. A primeira é a distinção entre formas lógicas, no sentido de propriedades lógicas de caráter abstrato, e forma lógica, no sentido em que falamos da forma lógica de uma sentença ou de uma proposição. A segunda é a distinção, enfatizada por Boole, entre proposições primárias e proposições secundárias , exemplificada com a distinção entre negação predicativa e negação sentencial. (shrink)

The booklet provides teachers and others who use the textbook "Logic" by Srećko Kovač with basic theoretical and philosophical ideas about logic as a discipline, as well as practical instructions on how to use the textbook.

In The Form of Truth: Hegel’s Philosophical Logic, Elena Ficara offers a reappraisal of G.W.F. Hegel’s logic within the history of logic and in relation to the logics of today. She brings together...

Introduction 1.1 GOALS This book is devoted to an in-depth investigation of some of the properties of Logical Form (LF). In particular, the primary aim of ...