ABSTRACT: A comprehensive introduction to ancient (western) logic from earliest times to the 6th century CE, with an emphasis on topics which may be of interest to contemporary logicians. Content: 1. Pre-Aristotelian Logic 1.1 Syntax and Semantics 1.2 Argument Patterns and Valid Inference 2. Aristotle 2.1 Dialectics 2.2 Sub-sentential Classifications 2.3 Syntax and Semantics of Sentences 2.4 Non-modal Syllogistic 2.5 Modal Logic 3. The early Peripatetics: Theophrastus and Eudemus 3.1 Improvements and Modifications of Aristotle's Logic 3.2 Prosleptic Syllogisms 3.3 Forerunners (...) of Modus Ponens and Modus Tollens 3.4 Wholly Hypothetical Syllogisms 4. Diodorus Cronus and Philo the Logician 5. The Stoics 5.1 Logical Achievements Besides Propositional Logic 5.2 Syntax and Semantics of Complex Propositions 5.3 Arguments 5.4 Stoic Syllogistic 5.5 Logical Paradoxes 6. Epicurus and the Epicureans 7. Later Antiquity. (shrink)

A lo largo de la tradición psicopatológica, incluso de la pre-fenomenológica, se encuentra la categorización del delirio como creencia. Jaspers asumió ese uso y lo fundó fenomenológico-existencialmente, definiendo su carácter de convicción. El concepto de creencia ha tenido un largo recorrido dentro de la historia del pensamiento, aunque recientemente se ha intensificado el debate acerca de la visión doxástica del delirio. En virtud de lo ya mencionado, en el presente artículo presentamos un análisis conceptual de la creencia, con el objetivo (...) de identificar de manera precisa los aspectos esenciales que permiten al delirio definirse según ella. De esta manera, se discutirán algunas de las principales incursiones realizadas en el concepto desde la antigüedad periplatónica hasta José Ortega y Gasset, remarcando en cada pensador las directrices esenciales de su aproximación a la creencia. A su vez, introducir al filósofo español al debate psicopatológico permitirá incluir en la discusión dos aspectos importantes que creemos pueden ser fructíferos para la discusión filosófica sobre el delirio: la diferencia entre ideas y creencias, y la vitalidad de estas últimas. Finalmente, hacemos referencia al actual debate pro- y antidoxástico, haciendo hincapié en la necesidad de considerar la amplitud del concepto de creencia en su genealogía histórica. Con base en ello estaríamos en condición de acercarnos a la visión doxástica moderada que han defendido autoras como Lisa Bortolotti. (shrink)

This article argues that a fragment from a lost treatise by Abū Bakr al-Rāzī (d. 925) is preserved in the Book on Morphology Kitāb al-Taṣrīf) by Ps-Ǧābir ibn Ḥayyān. Paul Kraus reached the conclusion that the collection to which this book belongs was written between the end of the ninth and the beginning of the tenth century AD. This fragment represents the first attempt – to our knowledge – to analyze the logical structure of sign-based inference in Arabic, which is (...) known as istidlāl bi-al-šāhid ʿalā al-ġāʾib among theologians and philosophers. The author distinguishes between sign-inferences based on homogeneity (al-muǧānasa), course of habit (maǧrā al-ʿāda) and traces (āṯār). After providing a translation of the fragment, the first part of this paper argues that its author is Abū Bakr al-Rāzī. My argument is based on a comparison between this text and a passage from the Doubts About Galen, which is also by Abū Bakr al-Rāzī. I hypothesize that at least two other fragments from the same work or from different works by Abū Bakr al-Rāzī are preserved in the corpus attributed to Ps-Ǧābir. The second part of the paper aims to reconstruct Abū Bakr al-Rāzī’s theory of sign-inference. In so doing, I show the historical influence that Hellenistic debates on sign-inference might have had on al-Rāzī, and I situate al-Rāzī’s theory in the context of the prominent use that the theologians of the kalām made of the istidlāl bi-al-šāhid ʿalā al-ġāʾib. To offer a more comprehensive reconstruction of al-Rāzī’s theory of sign-inference, this article compares the critical approach presented in the newly identified fragment with the epistemological framework outlined in the Doubts About Galen. Finally, this article shows that Abū Bakr al-Rāzī’s theory of sign-inference had a strong influence on al-Fārābī’s logical developments especially in his Epitome of the Prior Analytics, even if he does not acknowledge this intellectual debt. (shrink)

Philodemus’ De signis is one of the classical texts of greatest semiotic interest. It reports the debate which arose between the Epicureans and an opposing school, usually identified as the Stoics, concerning semiotic inference. The Epicureans proposed to construct semiotic inferences based on generalizations resting on similarity, ultimately configuring their method as a form of induction. Their opponents attacked the Epicurean proposal in a twofold way: on the one hand, they argued that the Epicureans’ method intrinsically lacked cogency, invalidating their (...) inferences from a logical point of view. On the other, they criticized the notion of similarity, arguing that it is generally a vague notion, and in some cases impossible to implement, as when one is faced with unique cases. The debate is very complex and is divided into replies and rejoinders. The ultimate impression one gets is that the Epicureans were able, for the first time in antiquity, to propose a real method to construct semiotic inferences, even though the latter were subject to fallibility, while their opponents did not propose a method, but a test, “elimination,” able only to check the logical soundness of semiotic inferences. In doing so, they placed themselves in a tradition extending back to the theory of signs formulated – albeit in a significantly different way – by Aristotle. (shrink)