Besides his translation of this classic, the author provides an introduction which serves to situate Galen and his work in ancient thought, an analysis which discusses Galen's sources, and a concise summary of the work itself. This volume should be of value to the modern logician as well as the student of ancient and medieval philosophy.—B. P. H.

An exploration of Galen's views on logic and the use of logic, including discussion of his work Institutio Logica and its introduction of a new kind of 'relational' syllogism, and the views about the fourth figure falsely attributed to him.

ABSTRACT: This paper traces the evidence in Galen's Introduction to Logic (Institutio Logica) for a hypothetical syllogistic which predates Stoic propositional logic. It emerges that Galen is one of our main witnesses for such a theory, whose authors are most likely Theophrastus and Eudemus. A reconstruction of this theory is offered which - among other things - allows to solve some apparent textual difficulties in the Institutio Logica.

ABSTRACT: Galen’s Institutio Logica is the only introduction to logic in Greek that has survived from antiquity. In it we find a theory that bears some resemblance to propositional logic. The theory is commonly understood as being essentially Stoic. However, this understanding of the text leaves us with a large number of inconsistencies and oddities. In this paper I offer an comprehensive alternative interpretation of the theory. I suggest that it is Peripatetic at base, and has drawn on (...) Stoic elements, but adapted them to an overall decidedly non-Stoic conception of logic and language, a conception indebted to Aristotelian logic in many respects. This interpretation makes it possible to reduce the seeming inconsistencies dramatically. The Peripatetic theory on which Galen draws was possibly developed in the first century BCE. Importantly, it differs from Stoic logic in that it shuns the latter’s syntactic approach, and considers certain linguistic assumptions and language conventions as part of the logical theory itself. My reconstruction of the theory results in a logic of propositions which differs wildly both from Stoic logic and from the ‘classical’ propositional logic of the 20th century. Interestingly, though, the theory in Galen shows that the ancients grappled with a number of logico-linguistic problems that over the last two decades have again become a matter of debate among contemporary logicians and linguists. (shrink)

Em minha tese de doutorado defendi que, para compreender como Hegel articula a passagem da contradição dialética à lógica, o conceito hegeliano de contradição deve ser analisado sob a perspectiva de uma antinomia. Para sustentar este argumento, propus uma atualização deste conceito a partir de uma estrutura antinômica. Essa atualização, porém, trouxe um outro problema: nessa reconstrução, a contradição, em Hegel, continua a se desenvolver de maneira gradativa, ao passo que a lógica tradicional trabalha apenas com valores de p e (...) -p, e não com níveis de gradação. Assim, para continuar sustentando o argumento de que o conceito hegeliano de contradição, sob a perspectiva de uma antinomia, pode ser compreendido como uma contradição lógica, seria necessário encontrar uma lógica que não operasse apenas com valores binários, mas também com níveis de gradação. Foi a partir dessa necessidade que surgiu a ideia de aplicar o conceito de contradição em Hegel à Lógica Difusa, e esta é, portanto, a proposta do presente artigo. (shrink)

La teoría de la disciplina formal sostiene que el estudio de las matemáticas desarrolla las habilidades lógicas de los individuos. Attridge e Inglis realizaron un experimento con el fin de comprobar si esta teoría es correcta o no. Su conclusión fue que sus resultados mostraban que, si bien las matemáticas pueden, efectivamente, mejorar las capacidades lógicas, es necesario asumir la interpretación defectuosa del condicional. Sin embargo, López-Astorga contraargumentó que eran posibles otras interpretaciones de sus resultados, que tales resultados no prueban (...) que la interpretación material del condicional no es válida y que la teoría de los modelos mentales también los puede explicar. En este trabajo, comento los problemas vinculados a las otras interpretaciones posibles propuestas por López-Astorga y trato de mostrar que la mejor opción para la interpretación de los resultados de Attridge e Inglis es asumir la teoría de la lógica mental. (shrink)

Standardly, the usual approach to rationality is based on the notion of ‘being a reason for’. Honouring the traditional distinction between practical and theoretical philosophy, reasons are classified as justificative and explicative. In both cases, a reason-statement has the form ‘’. For reasons of type , ‘A’ is a factual statement and ‘B’ is a statement which describes an action of the agent. The reason-statement has a prescriptive sense because ‘A is a reason for doing B’ means ‘A is a (...) reason an agent ought to do B’. So, it is advisable to schematize that kind of statements as ‘’, where ‘OB’ is a deontic statement prescribing the duty to do B. Reasons of type have a descriptive sense and do not require the above-mentioned constraint. But ‘being a reason for’ has different senses according to context, even when the distinction between justificative and explicative reasons is drawn. Accordingly, it is important to distinguish two basic types of reasons: sufficient and necessary, and two subordinate types of reasons: contributing and substitutive . A lot of attention has been paid, lately, to a sense of contributive reasons: prima facie reasons . The paper will deal with that kind of reasons. Its main thesis are: 1) prima facie reason-statements are defeasible conditionals ‘’ pointing out that A is a contributing condition of B, 2) a defeasible conditional has the properties of ‘’, where ‘ =>’ is a strict implication and ‘f’’ a revision-operator satisfying the conditions set up by the theory AGM on the rational change of theories. (shrink)

The 'Perutilis logica' is both by its content and its didactic value the most paradigmatic logical compendium of the 14th century. The study presented here tries to show on the basis of an interpretative analysis of the second treatise that the doctrine of the properties of terms is stated in a unusually developed form in the 'Perutilis logica' and that suggestions that it lacks originality must be revised.

My paper aims to analyse the Platonic conception of ontological ὰλήθεια and verify whether or not this conception depends on the etymological origin of the Greek word as a derivative noun from λανθάνειν. I shall start my inquiry by referring to Heidegger’s philosophical characterisation of ὰλήθεια as Unverborgenheit, and move on to quote relevant passages from the Homeric poems. I shall try to demonstrate – through the evidence from some key-passages of the Republic, the Phaedo, the Phaedrus and the Philebus (...) – that, even if we can find an ontological conception of the truth in Plato, this does not depend on the Greek etymology of ὰλήθεια, but rather on the archaic correspondance between being and thought. (shrink)

This paper is divided into three parts. The first part addresses the main tenets of Husserl ‘s conception of formal logic, its different levels and its relationship with formal mathematics and formal ontology. It will, therefore, undertake a delimitation of the logical domain, in its autonomy, taking as its point of departure the presentation Husserl makes of this subject in his works of maturity, particularly in Forma/e und. transzendentale Logik. The second ·part shows why, for phenomenology, the analysis of objective (...) logical configurations has to be completed by a subjective analysis of the intentional achievements in which these configurations have their genesis. ln other words, we will try to ground such an autonomy in. the very nature of logical reason. Finally, the third and last part, following the text of the first two sections of Erfahrung und Urteil, adresses the roots of the logical-categorical activity in the ante-predicative passive experience. (shrink)