This chapter contains sections titled: Introduction Relevant Logic Paraconsistent Logic Dialetheism Boolean Negation The Logical Choice Conclusion.

Among the subject matters which logicians like at times to investigate are the forms of postulation that other branches of inquiry employ. Rarely, however, do they examine the postulates under which they themselves proceed. It long contented them to offer something they called a “definition” for logic, and let it go at that. They might announce that logic dealt with the “laws of thought,” or with “judgment,” or that it was “the general science of order“; More recently they are (...) apt to connect it in one or another obscure way with linguistic ordering. (shrink)

One of the most influential logicians of the day has assembled and in part rewritten a number of his essays on important questions of logical theory. 1 The result is a most impressive book, at once powerful and graceful, and breathing a certain intellectual hauteur r which accords well with its conspicuous property of being intellectually first rate. These are not humble analytical gropings, undertaken by the dim light of an author’s sense of the sensible; but a series of (...) campaigns in abstract metaphysics, directed from the firm ground of mastery of a rigorous and exacting technique. “Those of us who have a taste for desert landscapes” is a phrase of the author’s. With a Roman ruthlessness he makes a solitude in which he can quantify peacefully over lumps of rock. (shrink)

The Polish School of Logic flourished in the period 1920-1939. Philosophically, it was influenced by Kazimierz Twardowski, professor at the University of Lwow (now Lviv in Ukraine), who established the Lwow-Warsaw School, to which the mentioned logical group belonged. Twardowski claimed that logic is very important in every kind of human activity, professional as well as private. Hence, every argument should be clearly formulated and proceed by correct inferential rules. These postulates involved semiotics, formal logic, and methodology of science — (...) that is, logica sensu largo. This position was accepted by Twardowski’s most distinguished students, such as Jan Łukasiewicz, Stanisław Leśniewski, Kazimierz Ajdukiewicz, and Tadeusz Kotarbiński, who graduated before 1914, as well as the next generation of logicians and philosophers, particularly by Alfred Tarski. Although all these people considered logic, philosophy, and science as completely neutral with respect to politics and ideology, they treated logical skills as indispensable in political activities. In philosophical specialized terminology, Polish logicians regarded logic as a weapon against irrationalism. This position was also represented by Polish logicians who did not belong to the group of Twardowski’s students. (shrink)

The paper examines the interplays between logic and politics in the Polish School of Logic starting from 1914. The Polish School of Logic flourished between 1920 and 1939. Philosophically, it was influenced by Kazimierz Twardowski (1866–1938). For Twardowski logic is fundamental for every kind of human activity, professional and private and this means that every argument should be formulated and proceed by correct inferential rules. These rules involve semiotics, formal logic and methodology of science. The paper shows how this position (...) was shared by Twardowski’s students, including Jan Łukasiewicz, Stanisław Leśniewski, Kazimierz Ajdukiewicz and Tadeusz Kotrabiński, as well as by the next generation of logicians and philosophers and especially by Alfred Tarski. These authors considered logic, philosophy and science as completely neutral with respect to politics and ideology but they also considered logical skills as indispensable in political activities. (shrink)

Non‐classical logicians do not typically reject classically valid logical principles across the board. In fact, they sometimes suggest that their preferred logic recovers classical reasoning in most circumstances. This idea has come to be known in the literature as ‘classical recapture’. Recently, classical logicians have raised various doubts about it. The main problem is said to be that no rigorous explanation has been given of how is it exactly that classical logic can be recovered. The goal of the (...) paper is to address this problem. First, I discuss a number of different ways to characterize the idea of classical recapture and I examine how far it can be pushed. Secondly, I argue that a palatable form of classical recapture is given by the thought that classical logic can be retained for statements that are grounded (in Kripke’s sense). To substantiate this view I provide a formal fixed‐point semantics for a language containing a predicate standing for the concept of groundedness and I address a couple of objections that have been deployed against the claim that classical recapture can aid the non‐classical logician’s cause. (shrink)

ABSTRACTLloyd argues for the value of analogical reasoning in helping to open cross-cultural perspectives in philosophy. In doing so he aims some strong criticism at the Western analytic philosophical tradition. Yet Lloyd's message is one which logicians working within the Western analytic tradition can and do embrace.

Studies Plato's approach to argumentation, exploring his role as logician, rhetorician, and dialectician in a way that sees these three aspects working together.

The combination of quantifiers with a semantics for epistemic operators in a modal framework is one of the major contributions of Hintikka in intensional logic. Hintikka’s starting point is his diagnosis of the failure of existential generalization and the substitution of identicals in terms of referential multiplicity. In this paper, I introduce Hintikka as a free logician. Indeed, Hintikka’s first-order epistemic logic is grounded on a logic free of ontological presuppositions with respect to singular terms. It is also a logic (...) free of presuppositions of uniqueness of reference. After having focused on the use of quantifiers and singular terms in Hintikka’s epistemic logic, I discuss some consequences from a semantico-logical perspective, but also from a philosophical one. By arguing against the so-called contingent a priori truths defended by Kripke, I conclude with a proposal in favour of Hintikka’s non-rigid interpretation of proper names. (shrink)

The logical rule of contraposition as applied to a particular affirmative proposition (I-contraposition), despite its rejection in the medieval Latin logic, had a different history in the medieval Arabic logic, varying from common acknowledgement to total dismissal (it was accepted by Avicenna and by all of his followers in the eleventh and twelfth centuries and rejected by all of Arabic logicians in the late thirteenth century onwards). This paper is a narrative of the fate of I-contraposition in the early (...) Arabic logic. I will study Avicenna’s, al-Suhrawardī’s, al-Rāzī’s, al-Kashshī’s, and al-Khūnajī’s views on this rule. Although Avicenna explicitly acknowledged I-contraposition in a brief note, and in an apparently Meinongian language, the other four figures found I-contraposition problematic and listed some counterexamples to it. Nonetheless, they all attempted to justify Avicenna’s acceptance of the rule by restricting its application conditions. These efforts led to interesting syntactic and semantic analyses but gathered little attention from later medieval logicians. Finally, in the middle Arabic logic, the revised versions of I-contraposition were also declared invalid. (shrink)

Graph polynomials are graph parameters invariant under graph isomorphisms which take values in a polynomial ring with a fixed finite number of indeterminates. We study graph polynomials from a model theoretic point of view. In this paper we distinguish between the graph theoretic (semantic) and the algebraic (syntactic) meaning of graph polynomials. Graph polynomials appear in the literature either as generating functions, as generalized chromatic polynomials, or as polynomials derived via determinants of adjacency or Laplacian matrices. We show that these (...) forms are mutually incomparable, and propose a unified framework based on definability in Second Order Logic. We show that this comprises virtually all examples of graph polynomials with a fixed finite set of indeterminates. Finally we show that the location of zeros and stability of graph polynomials is not a semantic property. The paper emphasizes a model theoretic view. It gives a unified exposition of classical results in algebraic combinatorics together with new and some of our previously obtained results scattered in the graph theoretic literature. (shrink)

The author distinguishes a "term logic," where terms are the fundamental units, and a "sentential logic," where sentences are the fundamental units. Although this technical distinction is presented by Englebretsen as a war-like opposition throughout the entire history of logic, he reassures us that "no blood has been spilled". In recent times, the term-logic party has been eclipsed by the sentential-logic band; term logic is nowadays "almost mute". Only F. Sommers appears to proclaim the truth of term logic in the (...) twentieth century. The author's main goal is to "recount the history" of term logic through an examination of its three champions: Aristotle, Leibniz, and Sommers. The chronological sequence of these three logicians is a sequence towards perfection as well. The shortcomings of Aristotle's achievement are partially corrected by Leibniz and then fully repaired by Sommers, who finally extends the Aristotelian syllogistic into a "universal logic". Englebretsen himself has added "certain emendations and extensions in a modest way". (shrink)

Classical logic yields counterintuitive results for numerous propositional argument forms. The usual alternatives (modal logic, relevance logic, etc.) generate counterintuitive results of their own. The counterintuitive results create problems—especially pedagogical problems—for informal logicians who wish to use formal logic to analyze ordinary argumentation. This paper presents a system, PL– (propositional logic minus the funny business), based on the idea that paradigmatic valid argument forms arise from justificatory or explanatory discourse. PL– avoids the pedagogical difficulties without sacrificing insight into argument.

I examine the treatment of metaphor by medieval logicians and how it stemmed from their reception of classical texts in logic, grammar, and rhetoric. I consider the relation of the word 'metaphor' to the notions of translatio and transumptio, and show that it is not always synonymous with these. I also show that in the context of commentaries on the Sophistical Refutations metaphor was subsumed under equivocation. In turn, it was linked with the notion of analogy not so much (...) in the Greek sense of a similarity between two proportions or relations as in the new medieval sense of being said secundum prius et posterius. Whether or not analogy could be reduced to metaphor, or the reverse, depended on the controversial issue of the number of acts of imposition needed to produce an equivocal term. A spectrum of views is canvassed, including those found in the logic commentaries of John Duns Scotus. (shrink)

This paper examines whether Sherlock Holmes’ “Science of Deduction and Analysis,” as reconstructed by Hintikka and Hintikka The sign of three: Peirce, Dupin, Holmes, Indiana University Press, Bloomington, 1983), exemplifies a logic of discovery. While the Hintikkas claimed it does, their approach remained largely programmatic, and ultimately unsuccessful. Their reconstruction must thus be expanded, in particular to account for the role of memory in inquiry. Pending this expansion, the Hintikkas’ claim is vindicated. However, a tension between the naturalistic aspirations of (...) their model and the formal apparatus they built it on is identified. The paper concludes on suggestions for easing this tension without losing the normative component of the Hintikkas’ epistemological model. (shrink)

Aristotle (d. 322 BC) was the first philosopher in the history of thought to examine all modes and types of belief acquisition such as knowledge, supposition, error and indirectly imagination. In his _Prior Analytics_, which he wrote primarily to clarify his theory of demonstration, Aristotle examined in detail the syllogism, which he saw as the most important form of reasoning, and his analysis was subject to interpretation by different traditions of thought for centuries. Aristotle’s _Prior Analytics_ was translated into Arabic (...) in the classical period and later interpreted by many Islamic logicians. This article aims to show how Aristotle’s definition of the syllogism in the _Prior Analytics_ was taken up and interpreted in the Peripatetic Islamic logical tradition. These interpretations of the definition of the syllogism will provide us with an idea about the unique features of the commentaries on the _Prior Analytics_ in the Islamic world. Here, introductory information about the translation of the _Prior Analytics_ into Arabic and its commentators in Arabic will be given, Aristotle’s definition of the syllogism and its versions in Peripatetic Islamic logicians will be indicated, and the interpretation of the basic terms in the definition by Peripatetic Islamic logicians will be revealed. (shrink)

Logic as a subject has existed for a long time. Aristotle and the Stoics identified some of its principles, as did Indian logicians. And this ancient logic underwent an extraordinary mathematical development in the last hundred and fifty years. So logic certainly exists, at least as a branch of mathematics. The question is whether it is anything more than that.

Arthur N. Prior, in the Preface of Past, Present and Future, made clear his indebtedness to “the very lively tense-logicians of California for many discussions”. Strangely,with a notable exception of Copeland, there is no extensive discussion of these scholars in the literature on the history of tense logic. In this paper, I propose to study how Nino B. Cocchiarella, as one of the Californian tense-logicians, interacted with Prior in the late 1960s. By gathering clues from their correspondence available (...) at Virtual Lab for Prior Studies, I will highlight some of the differences between their views on tense-logic, which might still have far-reaching philosophical implications. I will conclude with a sketchof how to study in what ways Prior and Cocchiarella influenced some other Californian tense-logicians. (shrink)

In a chapter of - so to speak - an intellectual autobiography I sketch the reasons and ways I became a practitioning Meinongian logician. The way is a chain of transgressions, e.g., the transgression of extensionalism or of the law of excluded middle, and a struggle against widespread misinterpretations of Meinong's Gegenstandstheorie. Although the opposition towards Meinong's theory of objects persists in analytic philosophy, its main insights - that thought is intentional and that logic must be ontologically neutral - haven't (...) lost their attraction. Moreover: there is no substantive criticism to show that we cannot refer and truely predicate properties of intended objects regardless of their ontic status. (shrink)

In ancient philosophy, Logic was seen as the instrument and method of philosophy. However, sometimes detailed and profound discussions have been made about the demonstrativeness of philosophical sciences. Most philosophers have accepted that the mathematical sciences were especially demonstrative and likewise, most of the natural sciences are demonstrative for them. But can metaphysics be demonstrative or not? This is one of the fundamental issues around which the great debates were made in Islamic philosophy. While these issues are known to specialists (...) in this field, we can hardly find studies and research that deal with this issue to a sufficient degree and precise discussions in our day, I mean the issue of demonstrativeness of art of demonstration, art of dialectic, art of sophistry, art of rhetoric and art of poetry. It is clear that the peripatetic philosophers did not write a separate book or treatise on the issue of the demonstrativeness of the logical arts, but we can claim that they believed that all these arts were demonstrative and that they were extracted/abstracted using the art of demonstration. We can come across important phrases and statements that prove this claim between the lines of the books that these philosophers wrote in the science of logic. And while Aristotle is the founder of the science of logic, then how is it to be understood that there are practical particular examples and some easy rules of these arts? According to their texts, we can say that they believed that the actual performance of these arts by their actors in materials by particular and practical actions differs from extracting their universal rules by abstracting them from their materials through theoretical and analytical research. For example, the poems of the great poets; Homer and al-Mutanabbi, are particular works in the matter of the art of poetry performed by poets. The books written by Aristotle and Ibn Rushd in the art of poetry contain universal rules extracted abstractly from the materials of their particular poems. As for understanding the demonstrativeness of the remaining four arts, it is easier, but how should we understand the demonstrativeness of the art of demonstration itself? It seems that the peripatetic logicians also distinguished between applying demonstrative inferences to significant materials and extracting the universal rules of the art of demonstration from these materials. These five logical arts are not particular and practical things, but they are philosophical, demonstrative, and analytical studies for the peripatetic logicians in Islam. In this paper, we will try to draw attention to the issue of the demonstrativeness of the five arts and to open a new discussion about it based on some important sentences and phrases expressed by al-Fārābī, Ibn Zur‘a, Ibn Sīnā, Ibn Bājja and Ibn Rushd between the lines in their books, which they wrote in the field of logic and within different and multiple contexts. (shrink)

In the thirteenth century, the influential logician Afḍal al-Dīn al-Khūnajī departed from the Avicennan view that the subject matter of logic is “second intentions”. For al-Khūnajī, the subject matter of logic is “the objects of conception and assent”. His departure elicited intense and sometimes abstruse discussions in the course of subsequent centuries. Prominent supporters of Khūnajī's view on the subject matter of logic included Kātibī, Ibn Wāṣil and Taftāzānī. Defenders of Avicenna's view included Ṭūsī, Samarqandī and Quṭb al-Dīn al-Rāzī. This (...) article presents the outline of the development of this discussion down to the end of the fourteenth century and attempts to reconstruct the major arguments of both sides.Au xiiie siècle, l'influent logicien, Afḍal al-Dīn al-Khūnajī, se démarque du point de vue avicennien d'après lequel ce sont les “intentions secondes” qui forment le sujet de la logique. Pour al-Khūnajī, le sujet de la logique, ce sont “les objets des conceptions et des assentiments”. Cet écart par rapport à la formulation avicennienne va susciter, au cours des siècles suivants, d'intenses et parfois abstruses discussions. Dans le camp de ceux qui adhèrent au point de vue d'al-Khūnajī, on trouve des auteurs tels que Kātibī, Ibn Wāṣil et Taftāzānī. En revanche, Ṭūsī, Samarqandī et Quṭb al-Dīn al-Rāzī se rangent dans le camp des défenseurs du point de vue d'Avicenne. Cet article présente les grandes lignes qui marquent le développement de cette discussion jusqu'à la fin du xive siècle et tente de reconstruire les arguments des deux partis.Send article to KindleTo send this article to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle. Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply. Find out more about the Kindle Personal Document Service.POST-AVICENNAN LOGICIANS ON THE SUBJECT MATTER OF LOGIC: SOME THIRTEENTH- AND FOURTEENTH-CENTURY DISCUSSIONSVolume 22, Issue 1Khaled El-Rouayheb DOI: https://doi.org/10.1017/S0957423911000105Your Kindle email address Please provide your Kindle [email protected]@kindle.com Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Send article to Dropbox To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about sending content to Dropbox. POST-AVICENNAN LOGICIANS ON THE SUBJECT MATTER OF LOGIC: SOME THIRTEENTH- AND FOURTEENTH-CENTURY DISCUSSIONSVolume 22, Issue 1Khaled El-Rouayheb DOI: https://doi.org/10.1017/S0957423911000105Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Send article to Google Drive To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about sending content to Google Drive. POST-AVICENNAN LOGICIANS ON THE SUBJECT MATTER OF LOGIC: SOME THIRTEENTH- AND FOURTEENTH-CENTURY DISCUSSIONSVolume 22, Issue 1Khaled El-Rouayheb DOI: https://doi.org/10.1017/S0957423911000105Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Export citation Request permission. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Against the Greek LogiciansCharles E. ButterworthIbn Taimiyya. Against the Greek Logicians. Translated with an introduction and notes by Wael B. Hallaq. Oxford: Clarendon Press, 1993. Pp. lviii + 204. $55.00.Wael Hallaq's most readable translation of Ibn Taimiyya's famous work is complemented by a masterful introduction and intelligent, relevant footnotes. In addition, he has taken care to help the reader in many ways, adding, for example, a list (...) of the emendations he has made to the Arabic text as well as a table that details the correspondence between the paragraphs of his translation and the pages and lines within the more standard Arabic texts.The editor-translator's introduction sets forth Ibn Taimiyya's teaching in a clear and well-argued manner, something that is necessary given the repetitiveness and confusing arguments that characterize the original. Though Hallaq tends to reveal himself to be something of a partisan of Ibn Taimiyya's doctrines and thus to overstate the case for his author, this is a minor flaw. The strength of the Introduction is such that the student of logic or philosophy is compelled to indicate the problems in Hallaq's presentation, that is, to identify the reasons for not being persuaded by his exposition. [End Page 273] To do so, however, is merely a means of carrying the argument a step further and thus a compliment of sorts to Hallaq.As I see it, there are five areas where one might take issue with the editor-translator's presentation of Ibn Taimiyya's teaching. First, because he follows his author too closely, Hallaq relies too much on Avicenna and on Avicenna's commentators to present the position of the philosophers. He seems to ignore that the teaching of Avicenna—he whom Averroes would identify only as "that man"-—is problematic even for the philosophers. Second, Hallaq relies too much on secondary literature in order to present the history of philosophy. He would have been far better advised to trace the history of philosophy for himself, especially the history of medieval Islamic philosophy. By relying on others, especially those whose interpretations are open to major objections, he weakens his own presentation. This tendency becomes especially evident in what I take as a third point of criticism, namely, Hallaq's too ready conflation of the history of philosophy and consequent willingness to blame ancient and medieval philosophers for the folly of modern philosophers (see xxx, n. 98 and xviii:17-18). Worse, Hallaq eventually becomes so carried away with the desire to refute the ancient and medieval philosophers that he no longer cares about the evil consequences of modern philosophy (see xviii:8-xlix:20, esp. xlviii:8-29). Indeed, and this is the fourth criticism, so intent is Hallaq on confirming that Ibn Taimiyya has refuted the philosophers that he is content to call anyone a philosopher, even al-Suhrawardī, al-Baghdādī, al-Tūsī, and, wonder of wonders, Fakhr al-Dīn al-Rāzī (see xliv:4). Though he has good guidance for this from Ibn Taimiyya, one would hope for more objectivity from the critical scholar than from the engaged defender of the faith. Finally, Hallaq actually introduces Ibn Taimiyya's wider teaching rather than the argument of this book, thereby neglecting the primary function of an introduction to a book. Thus, of 91 notes in the Introduction that refer to Ibn Taimiyya's works, only slightly more than half (52) cite this work. The other 39 are to Ibn Taimiyya's other writings. Moreover, many of the 52 notes to this work also refer to other writings by Ibn Taimiyya.Thankful as we must be to Hallaq for this translation, it is most unfortunate that he chose not to be consistent in his translation of Arabic terms. Apparently, he thought he could make more sense of Ibn Taimiyya's argument by translating terms in accordance with what he took to be the sense of what Ibn Taimiyya wished to say rather than in accordance with what he actually says. Consequently, tasdīq (a term I would translate as "assent") is rendered as "judgment"; but so is hukm (see ¶¶ 5 and... (shrink)

InThe Many Faces of Realism and elsewhere, Hilary Putnam has presented an argument for the conclusion that there is no fact of the matter as to how many objects there are. In brief: “Carnap” says that a certain imaginary world contains three objects, ×1, ×2, and ×3. The “Polish logician” says that this same world must contain four other objects (×1 + ×2, ×1 + ×2 + ×3, etc.). Putnam maintains that there can be no fact of the matter as (...) to whether the imaginary world contains three or seven objects. I examine Putnam’s argument and find it, at bottom, unintelligible. (shrink)

What is it that turns a new observation into a true scientific discovery? And who may claim the credit? Theoreticians of science, the foremost thinkers of their times among them, have tried to answer these fundamental questions about the nature of scientific progress and discovery. With clear insight and the chemical as well as philosophical wisdom gained from over fifty years as a practising chemist, Jerome Berson puts their theories to the test. The development of chemistry into a "modern" science (...) during the last two centuries provides him with ample cases to illustrate the way scientific progress really happens. Kekul?'s struggle to arrive at a structure for benzene, the paradigm change that was necessary to accept the reality of molecular rearrangements, and other episodes are retold here from the philosopher's as well as from the practitioner's perspective, shedding light on the way scientists think and act. Berson's account of the rather unphilosophical way in which scientific discoveries are made includes the realization that even a false hypothesis, such as Woodward's ideas about the biosynthesis of strychnine, may help rather than hinder scientific progress. Scientists of all ages, as well as many non-scientists, will find this a highly readable and unusual book. (shrink)

Peano's contributions to logic are surveyed under several headings. His use of class abstraction is considered first, together with his recognition of the distinction between membership and inclusion. Then his strategy of notational inversion is appraised. Finally, class abstraction is considered again, from ontological points of view; and Peano's achievements are compared with Frege's.

This brief note raises the question of why there is no advice in the literature for young logicians, while there is for mathematicians, musicians, and others. Trying to take advantage of what exists in other areas, some tendencies in logic, and reasons to follow – or not to follow-- trends are discussed.

In recent years, commentators have begun to re-examine the proximity of Frantz Fanon's and Jacques Lacan's work — a proximity which has traditionally been underappreciated. This article adds to these voices, demonstrating the reciprocal intellectual relationship between these two figures. It develops five interrelated arguments to chart this proximity. First, it emphasizes Lacan's and Fanon's connections through their ontological perspectives on madness. Second, it arbitrates the two theorists’ criticisms of the limits of Western psychoanalysis. Third, it shows the importance placed (...) by both on social structures in determining mental illnesses. Next, it demonstrates the centrality of their common understanding of psychosis. Finally, it argues that Lacan's argument in The Sinthome concerning the colonizer's power is inherited from Fanon's Black Skin, White Masks — itself influenced by Lacan's early theory of language. The article does not attempt to cast Fanon as an apprentice Lacanian but rather to argue that reciprocity helped shape both oeuvres. (shrink)

We define and examine a notion of logical friendliness, which is a broadening of the familiar notion of classical consequence. The concept is studied first in its simplest form, and then in a syntax-independent version, which we call sympathy. We also draw attention to the surprising number of familiar notions and operations with which it makes contact, providing a new light in which they may be seen.