¿Cómo puede la lógica representar expresiones indéxicas como “yo”, “aquí” y “ahora”? ¿Cómo no debe representarlas? Examino estas dos preguntas a partir de la Lógica de los Demostrativos (LD) de Kaplan y su impopular prohibición de operadores monstruosos. A pesar de algunos defectos de formulación, sostengo que dicha prohibición está guiada por una poderosa visión de las relaciones lógicas de validez entre oraciones con indéxicos que desafía la concepción tradicional de consecuencia lógica como preservación de la verdad y resalta el (...) papel fundamental de la información semántica en la construcción de sistemas formales concebidos como modelos de las lenguas naturales. (shrink)

Este trabajo analiza los patrones de desambiguación de presuposiciones que se pueden considerar anafóricas y son generadas por partículas indexicales. En contraste con teorías recientes sobre la presuposición que privilegian la información lexical proponemos un análisis perspectivo de la presuposición según el cual la inferencia por defecto sobre este tipo de información hace uso de la perspectiva de los hablantes. En dos estudios exploramos el patrón de desambiguación de oraciones que contienen la palabra ‘también’ en contextos donde se usa el (...) indéxico ‘yo’. Los resultados confirman nuestra hipótesis y se discuten a la luz las principales ideas sobre presuposición y anáfora. A partir de estos resultados sugerimos algunas direcciones futuras de investigación. (shrink)

Motivated by H. Curry’s well-known objection and by a proposal of L. Henkin, this article introduces the positive tableaux, a form of tableau calculus without refutation based upon the idea of implicational triviality. The completeness of the method is proven, which establishes a new decision procedure for the (classical) positive propositional logic. We also introduce the concept of paratriviality in order to contribute to the question of paradoxes and limitations imposed by the behavior of classical implication.

El presente artículo ofrece una interpretación original del trabajo de Austin sobre la aserción y los adverbios y deriva de ella una semántica expresivista para las oraciones de acción. En primer lugar, el análisis austiniano de la aserción con su idea de fuerzas asertivas específicas se conecta sistemáticamente con sus observaciones sobre la modificación adverbial para obtener esquemas de aserción para oraciones de acción. En segundo lugar, se interpretan esos esquemas en términos de la expresión de los compromisos inferenciales propios (...) de prácticas argumentativas exculpatorias, justificativas y ejemplarizantes en las que se explota la contrariedad lógica a la par de la contradicción. This paper offers a new interpretation of John Austin's views both on assertion and on adverbs, as result of which an expressivist thesis concerning the semantics for action sentences is advanced. First, Austin's analysis of assertion based on various, specific assertive forces and his remarks on adverbs are systematically connected in order to obtain assertive schemata for action sentences. Finally, those schemata are put to work as the expression of inferential commitments implicit in argumentative practices of different sorts in the deployment of which both logical contrariety and contradiction are exploited. (shrink)

This work studies some problems connected to the role of negation in logic, treating the positive fragments of propositional calculus in order to deal with two main questions: the proof of the completeness theorems in systems lacking negation, and the puzzle raised by positive paradoxes like the well-known argument of Haskel Curry. We study the constructive com- pleteness method proposed by Leon Henkin for classical fragments endowed with implication, and advance some reasons explaining what makes difficult to extend this constructive (...) method to non-classical fragments equipped with weaker implications (that avoid Curry's objection). This is the case, for example, of Jan Lukasiewicz's n-valued logics and Wilhelm Ackermann's logic of restricted implication. Besides such problems, both Henkin's method and the triviality phenomenon enable us to propose a new positive tableau proof system which uses only positive meta-linguistic resources, and to mo- tivate a new discussion concerning the role of negation in logic proposing the concept of paratriviality. In this way, some relations between positive reasoning and infinity, the possibilities to obtain a ¯first-order positive logic as well as the philosophical connection between truth and meaning are dis- cussed from a conceptual point of view. (shrink)

In this work I argue for the thesis that Grice’s intentional-cooperative analysis of assertion works at three levels: the logical, the epistemological and the normative. I use “conventional implicature” as example. First part shows that other approaches to assertion can’t give an accurate description of semantic content. I point to a general, twofold conclusion: the truth-conditional approach fails by neglecting intentional acts to be the meaning blocks; the rule-oriented approach misses its target by disregarding that all communicative acts are intentional, (...) but many are not conventional. Assertion includes some features of intentional action, the main theme in second part. As rational justification is the basis of intention, the solution of some remaining problems connected to assertion may rest in the justificatory structures underlying intention. Judgment, the epistemic variety of rational acceptability, determines, on one hand, the infelicity in conventional implicature cancellation and, on the other, shows why convention is just a minor component in the theory of meaning. Justification deems a special methodology in which causal explanations of meaning and representation can be replaced by justifications, teleological in character. The rationalist background of Grice’s proposal is thus stressed, as well as his conception of rationality as the body of capacities in charge of identifying and attributing value. Following this interpretation, other problems on meaning and communication, for example the relations between the Cooperative Principle and the conversational maxims, can be dealt with. (shrink)