The purpose of this note is to present a strong form of the liar paradox. It is strong because the logical resources needed to generate the paradox are weak, in each of two senses. First, few expressive resources required: conjunction, negation, and identity. In particular, this form of the liar does not need to make any use of the conditional. Second, few inferential resources are required. These are: (i) conjunction introduction; (ii) substitution of identicals; and (iii) the inference: From ¬(p (...) ∧ p), infer ¬ p. It is, interestingly enough, also essential to the argument that the ‘strong’ form of the diagonal lemma be used: the one that delivers a term λ such that we can prove: λ = ¬ T(⌈λ⌉); rather than just a sentence Λ for which we can prove: Λ ≡ ¬T(⌈Λ⌉). The truth-theoretic principles used to generate the paradox are these: ¬(S ∧ T(⌈¬S⌉); and ¬(¬S ∧ ¬T(⌈¬S⌉). These are classically equivalent to the two directions of the T-scheme, but they are intuitively weaker. The lesson I would like to draw is: There can be no consistent solution to the Liar paradox that does not involve abandoning truth-theoretic principles that should be every bit as dear to our hearts as the T-scheme. So we shall have to learn to live with the Liar, one way or another. (shrink)

This book is an introduction, entirely by example, to the possibilities of using computer models as tools in phosophical research in general and in philosophical logic in particular. Topics include chaos, fractals, and the semantics of paradox; epistemic dynamics; fractal images of formal systems; the evolution of generosity; real-valued game theory; and computation and undecidability in the spatialized Prisoner's Dilemma.

Der zweisprachige Band führt in die "Wiener Ausgabe" der Werke Ludwig Wittgensteins (1889-1951) ein, in der erstmals dessen Manuskripte vollständig und in getreuer Wiedergabe erscheinen werden. In jahrzehntelanger Arbeit wurde der Nachlaß mithilfe einer Editionsmethode ediert, die für dieses ungewöhnliche Werk speziell entwickelt wurde. Der Einführungsband erklärt diese Methode wie die editorische Situation des Nachlasses und stellt darüber hinaus Arbeitsunterlagen für das Studium von Wittgensteins Texten zur Verfügung: Eine biographische Skizze zeigt die Verbindung von Leben und Werk, eine schematische Chronologie (...) erleichert die Zuordnung der jeweiligen Manuskriptseiten und Typoskripte. Die Gegenüberstellung von Faksimileabdrucken einzelner Manuskriptseiten und der edierten Seiten läßt die einzelnen Schritte der Textedition transparent werden. (shrink)

Such a conception, says Dummett, will form "a base camp for an assault on the metaphysical peaks: I have no greater ambition in this book than to set up a base ...

This book provides an incisive, basic introduction to many-valued logics and to the constructions that are "many-valued" at their origin. Using the matrix method, the author sheds light on the profound problems of many-valuedness criteria and its classical characterizations. The book also includes information concerning the main systems of many-valued logic, related axiomatic constructions, and conceptions inspired by many-valuedness. With its selective bibliography and many useful historical references, this book provides logicians, computer scientists, philosophers, and mathematicians with a valuable survey (...) of the subject. (shrink)

The book has two parts: one metaphysical, the other epistemological. The metaphysical part is largely concerned with realism issues. It starts with realism about universals, dismissing Plato's notorious ‘one over many’ problem. Several chapters argue for a fairly uncompromisingly realist view of the external physical world of commonsense and science. Both the nonfactualism of moral noncognitivism and positivistic instrumentalism, and deflationism about truth, are found to rest on antirealisms about their subject matters that are hard to characterize. A case is (...) presented for moral realism. Various biological realisms are considered. Finally, an argument is presented for an unfashionable biological essentialism. The epistemological part of the book argues against the a priori and for a Quinean naturalism. The intuitions that so dominate ‘armchair philosophy’ are empirical not a priori. There is an emphasis throughout the book on distinguishing metaphysical issues about what there is and what it's like from semantic issues about meaning, truth, and reference. Another central theme, captured in the title, is that we should ‘put metaphysics first’. We should approach epistemology and semantics from a metaphysical perspective rather than vice versa. The epistemological turn in modern philosophy and the linguistic turn in contemporary philosophy were something of disasters. (shrink)

Introduction -- Metaphysics -- "Ostrich nominalism"' or "mirage realism"? -- Postscript to "Ostrich nominalism" or "mirage realism"? -- Aberrations of the realism debate -- Postscript to "aberrations of the realism debate" -- Underdetermination and commonsense realism -- Scientificrealism -- Postscript to "scientific realism" -- Incommensurability and the priority of metaphysics -- Postscript to "incommensurability and the priority of metaphysics" -- Global response dependency and worldmaking -- The metaphysics of nonfactualism -- The metaphysics of truth -- Moral realism : a naturalistic (...) perspective -- Natural kinds and biological realisms -- Resurrecting biological essentialism -- Epistemology -- Naturalism and the a priori -- No place for the a priori -- Intuitions -- On determining what there isn't. (shrink)

This PhD thesis is a careful discussion of Aristotle's Metaphysics VII (Zeta) almost line by line (or at least argument by argument). It might be interesting to know that a revised and shortened version of it was published as a book in Portuguese, "As Noções Aristotélicas de Substância e Essência", Campinas: Editora da Unicamp, 2008. Actually, I believe the original version of the PhD thesis has been superseded by the book.

The distinction between essential versus accidental properties has been characterized in various ways, but it is currently most commonly understood in modal terms: an essential property of an object is a property that it must have, while an accidental property of an object is one that it happens to have but that it could lack. Let’s call this the basic modal characterization, where a modal characterization of a notion is one that explains the notion in terms of necessity/possibility. In the (...) characterization just given of the distinction between essential and accidental properties, the use of the word “must” reflects the fact that necessity is invoked, while the use of the word “could” reflects that possibility is invoked. The notions of necessity and possibility are interdefinable: to say that something is necessary is to say that its negation is not possible; to say that something is possible is to say that its negation is not necessary; to say that an object must have a certain property is to say that it could not lack it; and to say that an object could have a certain property is to say that it is not the case that it must lack it. (shrink)

De modo geral, este texto é uma incursão em lógica filosófica e filosofia da lógica. Ele contém reflexões originais acerca dos conceitos de paraconsistência, modalidades e cognoscibilidade e suas possíveis relações. De modo específico, o texto avança em quatro direções principais: inicialmente, uma definição genérica de lógicas não clássicas utilizando a ideia de lógica abstrata é sugerida. Em seguida, é mostrado como técnicas manuais de paraconsistentização de lógicas são usadas para gerar sistemas particulares de lógicas paraconsistentes. Depois, uma definição de (...) possibilidade lógica é proposta por meio da ideia de limites de sequências de fórmulas. Por fim, muitas abordagens distintas ao paradoxo de Fitch e, consequentemente, aos limites do conhecimento são apresentadas considerando as reflexões anteriores. (shrink)

In this paper I will compare some of Dummett and Davidson’s claims on the problem of communication and idiolects: how can we understand each other if we use different idiolects? First I define the problem, giving the alternative theses of (I) the priority of language over idiolects and (II) the priority of idiolects over language. I then present Dummett's claims supporting (I) and Davidson's claims supporting (II).