Graham Priest's book In Contradiction is a bold defense of the existence of true contradictions. Although Priest's case is impressive, and many of his arguments are correct, his approach is not the only one allowing for true contradictions. As against Priest's, there is at least one contradictorialist approach which establishes a link between true contradictions and degrees of truth. All in all, such an alternative is more conservative, closer to mainstream analytical philosophy. The two approaches differ as regards the floodgate (...) problem. Priest espouses a confinement policy banning contradictions except in a few special domains, particularly those of pure semantics and set-theory , whereas the alternative approach admits two negations -- natural or weak negation and strong negation, the latter being classical; accordingly, the alternative approach prohibits any contradiction involving strong negation, thus providing a syntactic test of what contradictions have to be rejected. (shrink)
The main starting point of many of the contributions collected into the book is the kind of Twin Earth considerations, along with meaning individualism. Is Putnam's claim about water in this world and a stuff in an alternative world being different materials?. Is meaning in the head? One seems allowed to be skeptical about the starting point of the debate between such as emphasize broad content and those who think that the basic semantic entities are narrow contents, which would fail (...) to be world-dependent or world-oriented. The kind of motivations prompting the essays collected into the book are likely to be regarded as in need of a deeper elucidation by such as have been more or less influenced by Quine. Pettit & McDowell's collection of essays is one of the books most scholars interested in the confines of philosophy of language and philosophy of mind will find worth reading. (shrink)
Still, it is but fair for me to point out that several of the mainstays of the present proposal owe very little to the influence of the philosophers whose epistemological views have attracted me most — or for that matter to that of other analytical philosophers. I am referring to my acknowledging degrees of truth and existence and, consequently, degrees of knowledge, too.
In his 1686 essay GI Leibniz undertook to reduce sentences to noun-phrases, truth to being. Such a reduction arose from his equating proof with conceptual analysis. Within limits Leibniz’s logical calculus provides a reasonable way of surmounting the dichotomy, thus allowing a reduction of hypothetical to categorical statements. However it yields the disastrous result that, whenever A is possible and so is B, there can be an entity being both A and B. Yet, Leibniz was in the GI the forerunner (...) of 20th century combinatory logic, which (successfully!) practices - sometimes for reasons not entirely unlike Leibniz’s own grounds - reductions of the same kinds he tried to carry out. (shrink)
Three (apparent ) deontic antinomies are discussed: the paradoxes of the watchman and the praiser, as weIl as deontic dilemmas. A paraconsistent deontic logic, Ad, is put forward whose underlying 1st-order calculus is an infinite-valued tensorial logic. Several arguments are offered bearing out be existence of deontic contradictions, while two ways of dealing with conditional obligation paradoxes within the framework of Ad are canvassed. While the aggregation rule and the ought-implies-can principle are upheld, sundry schemata are shown not to obtain (...) which involve iterated deontic operators (most conspicuously: that whatever ought to be obligatory is obligatory; and that it is obligatory that whatever ought to be the case should in fact be the case). (shrink)
A comparative study of a broad range of logical systems, showing that classical logic is just one among them and thate there are useful nonclassical logics which are conservative extensions of classical logic, by risorting to several negations and several implications. The book is oriented towards a defense of fuzzy logics.
The paper goes into the intricate logical relation between imperatives, precepts and norms. It shows that there need not be two senses of "ought", the one descriptive and the other prescriptive, since when the law-giver enacts a fresh statute he is hereby making a tru statement, whose truth is grounded on the statement itself.
A Fuzzy-Set Theoretical Framework -resting on a paraconsistent infinite-valued logic- is sketched, wherein a thorough ontological-reduction program can be carried out. The framework includes formulae of the form “x comprises z in the time-interval e”. Reducing aggregates to sets thus handled is shown to escape usual objections. Likewise, systems generally can be regarded as aggregates, hence as (fuzzy) sets -the purported nonextensionality of systems objection being disposed of owing to our system’s recognizing infinitely many membership degrees. So do bodies, too, (...) which enables us to find a solutionto Unger’s sorites concerning ordinary material bodies. (shrink)
Many-Valued logics can harbour nonclassical connectives expressing truth-nuances. The course of development of many-valued logics has given rise to paraconsistent systems wherein a sentence can be both negated and asserted just in case it is only partly true. A recently implemented family of such logics is shown to be a useful tool in coping with a number of philosophical difficulties, such as Zeno’s paradox of the arrow. This family is somehow akin to fuzzy logics initiated by Zadeh, but unlike them (...) it contains as a tautology the principle of excluded middle. (shrink)
In his 1686 essay GI Leibniz undertook to reduce sentences to noun-phrases, truth to being. Such a reduction arose from his equating proof with conceptual analysis. Within limits Leibniz’s logical calculus provides a reasonable way of surmounting the dichotomy, thus allowing a reduction of hypothetical to categorical statements. However it yields the disastrous result that, whenever A is possible and so is B, there can be an entity being both A and B. Yet, Leibniz was in the GI the forerunner (...) of 20th century combinatory logic, which practices - sometimes for reasons not entirely unlike Leibniz’s own grounds - reductions of the same kinds he tried to carry out. (shrink)
Castañeda’s most significant insights iie in his awareness of serious ontologicaI problems, which beset usual treatments. Among this outstandlng proposals are these about the structure of relational facts, guise theory and the bundle view of individuals, the I, and practitions. Castañeda’s metaphysics Is one of the most remarkable achievements in anaytical philosophy.
The concept of every real thing from all eternity contains the unavoidability of its existence before the divine decision. Thus every complete concept of a real thing contains the property of being such that the thing will exist if a created universe exists. Then a thing's existence cannot be external to its concept. There is bound to be more in the concept of something that exists than in that of "something" that does not-since existence is explained through the quidditative property (...) of being an essence that constitutes an integral part of the most perfect series of things. Such an essential, quidditative perfection explains the divine decision, and hence existence. Therefore, existence can be deduced from that essential perfection. The essence-as-such, the mere possible, contains something from which existence follows. What Leibniz never manages to explain is what distinguishes existence from the quidditative perfection it unavoidably stems from. (edited). (shrink)
RésuméL'article examine la thèse leibnizienne de la tendance à l'existence de toutes les essences et de la réalisation de la série des êtres possibles qui, ensemble, ont le plus d'entité. Bien qu'elle offre une réponse à la question de savoir pourquoi il y a un monde – et pourquoi il s'agit du monde réel et non d'un autre –, la thèse se heurte à de nombreux obstacles. On tend actuellement àécarter les lectures nécessitaristes. L'article s'inscrit en faux contre cette tendance; (...) il vise à montrer les difficultés qui entourent l'interprétation de la nécessité fondée en théorie de la preuve, non seulement en général mais aussi en particulier par rapport à Leibniz. Une issue aux difficultés pourrait consister à développer la notion leibnizienne des degrés de réalité, en concevant aussi des degrés d'existence. Cela permettrait d'éviter la rupture entre l'ordre des possibles et celui des existants. Alors que Leibniz reconnaît des variations dans le degré d'entité des possibles, il est mené par son attachement à la logique aristotélicienne à faire du passage de la possibilitéà l'existence un bond métaphysique, l'actualitéétant ainsi rque comme une question de tout ou rien. Une approche gradualiste permettrait de concilier une partie des motivations métaphysiques de Leibniz avec un réalisme modal apparentéà celui de David Lewis, mais dûment nuancé. (shrink)
Recent work of Gustav Bergmann develops an ontological framework within which an account of relations has been sketched out. The approach is a kind of new logical atomism which has some of the features of an Aristotelian hylomorphism (of sorts). It recognizes a number of categories and groups of a hylomorphic kind, chiefly “determinates” and “subdeterminates”--the latter only indirectly or implicitly. Winsome though it is, the approach is flawed by certain difficulties it gives rise to, among them inability to speak (...) of subdeterminates and failure of a relation to be had by a referent towards a relatum. Instead of having a sense, a relation is conceived of as a determinate which enters an arrangement whose existence and nature are not properly accounted for. Finally, Bergmann’s Ideal Language is assayed and shown not to be as useful philosophically in itself as he takes it to be. (shrink)
Raul Orayen's book _Lógica, significado y ontología_ is a deep study into a range of issues in the philosophy of logic, taking Quine as the main interlocutor. It goes into subjects such as Truth-bearerss, Logical Truth, Validity, Propositions, Quine's Extensionalism, Relevant Logic and disjunctive syllogism, and Castañeda's ontology of Guises.