ABSTRACT: The mental models theory predicts that, while conjunctions are easier than disjunctions for individuals, when denied, conjunctions are harder than disjunctions. Khemlani, Orenes, and Johnson-Laird proved that this prediction is correct in their work of 2014. In this paper, I analyze their results in order to check whether or not they really affect the mental logic theory. My conclusion is that, although Khemlani et al.'s study provides important findings, such findings do not necessarily lead to questioning or to rejecting (...) the mental logic theory. RESUMO: A teoria dos modelos mentais prevê que, enquanto as conjunções são mais fáceis do que as disjunções, para os indivíduos, quando negadas, as conjunções são mais difíceis do que as disjunções. Khemlani, Orenes e Johnson-Laird provaram que essa previsão está correta, em seu trabalho de 2014. Neste trabalho, analiso os seus resultados, a fim de verificar se eles realmente afetam a teoria da lógica mental ou não. Minha conclusão é que, embora o estudo da Khemlani, Orenes and Johnson-Laird forneça resultados importantes, tais resultados não conduzem necessariamente a minar ou rejeitar a teoria da lógica mental. (shrink)

The double negation has always been considered by the logical systems from ancient times to the present. In fact, that is an issue that the current syntactic theories studying human reasoning, for example, the mental logic theory, address today. However, in this paper, I claim that, in the case of some languages such as Spanish, the double negation causes problems for the cognitive theories mainly based on formal schemata and supporting the idea of a universal syntax of thought in the (...) human mind. Thus, I propose that, given those problems, semantic frameworks such as that of the mental models theory seem to be more appropriate for explaining the human inferential activity. (shrink)

Stoic logic assumes five inference schemata attributed to Chrysippus of Soli. Those schemata are the well-known indemonstrables. A problem related to them can be that, according to standard propositional calculus, only one of them, modus ponens, is clearly indemonstrable. Nevertheless, I try to show in this paper that the mental logic theory enables to understand why the Stoics considered such schemata to be basic kinds of arguments. Following that theory, four of them can be linked to ‘Core Schemata’ of mental (...) logic and the only one that is more controversial is modus tollens. However, as I also comment, some assumptions of Stoic philosophy, which can be interpreted from the mental logic theory, can explain why this last argument was included into the set of the indemonstrablesas well. (shrink)

It is usually said that there is a clear difference between pre-philosophical texts such as Homer’s Iliad and what is provided in the fragments corresponding to first philosophers such as Thales of Miletus. This paper tries to show that this is not undoubtedly so, and it does that by means of the analysis of a fragment of the Iliad in which Hypnos is speaking. In this way, the main argument is that, while the fragment can be interpreted both in a (...) literal and in a metaphorical or poetic sense, in both of those cases it can be thought that it is related to philosophy or rational thinking. If the interpretation is literal, the fragment expresses an idea very akin to an important thesis by Thales of Miletus. On the other hand, if the interpretation is metaphorical or poetic, we have to assume, following several contemporary reasoning theories, that the fragment is essentially based on an evident rational inference. (shrink)

Drawing on the theory of ‘mental models’, I have previously shown that the valid syllogisms in the Aristotelian logical system, including all of its figures and moods, are very easy for the human mind. Indeed, they can even be used to predict inferences that people can make with quantified sentences. In this paper, I further argue that, if mental models theory is correct, then also the Aristotelian conversion rules are not hard for the human mind. My account here again focuses (...) on the distinction made by the mental models theory between canonical and noncanonical models. (shrink)

Resumen Atendiendo a la lógica estándar, solo uno de los cinco indemostrables propuestos por Crisipo de Solos es realmente indemostrable. Sus otros cuatro esquemas son demostrables en tal lógica. La pregunta, por tanto, es: si cuatro de ellos no son verdaderamente indemostrables, por qué Crisipo consideró que sí lo eran. López-Astorga mostró que si ignoramos el cálculo proposicional estándar y asumimos que una teoría cognitiva contemporánea, la teoría de la lógica mental, describe correctamente el razonamiento humano, se puede entender por (...) qué Crisipo pensó que todos sus indemostrables eran tan básicos. No obstante, en este trabajo trato de argumentar que la teoría de la lógica mental no es el único marco que puede explicar esto. En concreto, sostengo que otra importante teoría sobre el razonamiento en el presente, la teoría de los modelos mentales, también puede ofrecer una explicación al respecto.According to standard logic, only one of the five indemonstrables proposed by Chrysippus of Soli is actually indemonstrable. The other four schemata are demonstra-ble in that logic. The question hence is, if four of them are not really indemonstrable, why Chrysippus considered them to be so. López-Astorga showed that, if we ignore standard propositional calculus and assume that a current cognitive theory, the mental logic theory, truly describes human reasoning, it can be explained why Chrysippus thought that all of his indemonstrables were so basic. However, in this paper, I try to argue that the mental logic theory is not the only framework that can account for that. In particular, I hold that another important reasoning theory at present, the mental models theory, can offer an explanation in that regard as well. (shrink)

The current formal theories trying to account for reasoning and language often need to resort to the thesis of the pragmatic or implicit premises to explain the real role pragmatics plays in the human inferential activity. The main aim of this paper is to show that, although they did not propose theories in this way, the Stoics, by means of their concept of ‘sign’, already offered the essential arguments and foundations necessary to describe the real action of both pragmatics and (...) the premises coming from general knowledge when we make inferences. (shrink)

Šiuo straipsniu mėginama parodyti, jog Indijos ir stoikų logika yra panašesnės viena į kitą nei į standartinę logiką. Šiuo tikslu analizuojama ištrauka iš Kathāvatthu, kurioje pateikiamas sąlyginio teiginio apibrėžimas dažnai interpretuojamas kaip atitinkantis modernioje teiginių logikoje vartojamą materialiosios implikacijos sampratą. Teigiama, jog tokia interpretacija nėra visiškai pagrįsta. Todėl daroma išvada, jog tai, kas iš tiesų sakoma aptariamoje ištraukoje, nuosekliai susiję su Chrisipo Soliečio pasiūlytu sąlyginio teiginio teisingumo kriterijumi.