Current practice in logic increasingly accords recognition to abductive, presumptive or plausible arguments, in addition to deductive and inductive arguments. But there is uncertainty about what these terms exactly mean, what the differences between them are (if any), and how they relate. By examining some analyses ofthese terms and some of the history of the subject (including the views of Peirce and Cameades), this paper sets out considerations leading to a set of definitions, discusses the relationship of these three forms (...) of argument to argumentation schemes and sets out a new argumentation scheme for abductive argument. (shrink)

The Generative Lexicon presents a novel and exciting theory of lexical semantics that addresses the problem of the "multiplicity of word meaning" - that is, how ...

This book offers a new approach to the analysis of the multiple meanings of English modals, conjunctions, conditionals, and perception verbs. Although such ambiguities cannot easily be accounted for by feature-analyses of word meaning, Eve Sweetser's argument shows that they can be analyzed both readily and systematically. Meaning relationships in general cannot be understood independently of human cognitive structure, including the metaphorical and cultural aspects of that structure. Sweetser shows that both lexical polysemy and pragmatic ambiguity are shaped by our (...) metaphorical folk understanding of epistemic processes and of speech interaction. Similar regularities can be shown to structure the contrast among root, epistemic and speech act uses of modal verbs, multiple uses of conjunctions and conditionals, and certain processes of historical change observed in Indo-European languages. Since polysemy is typically the intermediate step in semantic change, the same regularities observable in polysemy can be extended to an analysis of semantic change. (shrink)

The term fuzzy logic is used in this paper to describe an imprecise logical system, FL, in which the truth-values are fuzzy subsets of the unit interval with linguistic labels such as true, false, not true, very true, quite true, not very true and not very false, etc. The truth-value set, , of FL is assumed to be generated by a context-free grammar, with a semantic rule providing a means of computing the meaning of each linguistic truth-value in as a (...) fuzzy subset of [0, 1].Since is not closed under the operations of negation, conjunction, disjunction and implication, the result of an operation on truth-values in requires, in general, a linguistic approximation by a truth-value in . As a consequence, the truth tables and the rules of inference in fuzzy logic are (i) inexact and (ii) dependent on the meaning associated with the primary truth-value true as well as the modifiers very, quite, more or less, etc. (shrink)

We contend that it is possible to argue reasonably for and against arguments from classifications and definitions, provided they are seen as defeasible (subject to exceptions and critical questioning). Arguments from classification of the most common sorts are shown to be based on defeasible reasoning of various kinds represented by patterns of logical reasoning called defeasible argumentation schemes. We show how such schemes can be identified with heuristics, or short-cut solutions to a problem. We examine a variety of arguments of (...) this sort, including argument from abductive classification, argument from causal classification, argument from analogy-based classification and arguments from classification based on generalizations. (shrink)

Six experiments explored the hypothesis that the members of categories which are considered most prototypical are those with most attributes in common with other members of the category and least attributes in common with other categories. In probabilistic terms, the hypothesis is that prototypicality is a function of the total cue validity of the attributes of items. In Experiments 1 and 3, subjects listed attributes for members of semantic categories which had been previously rated for degree of prototypicality. High positive (...) correlations were obtained between those ratings and the extent of distribution of an item's attributes among the other items of the category. In Experiments 2 and 4, subjects listed superordinates of category members and listed attributes of members of contrasting categories. Negative correlations were obtained between prototypicality and superordinates other than the category in question and between prototypicality and an item's possession of attributes possessed by members of contrasting categories. Experiments 5 and 6 used artificial categories and showed that family resemblance within categories and lack of overlap of elements with contrasting categories were correlated with ease of learning, reaction time in identifying an item after learning, and rating of prototypicality of an item. It is argued that family resemblance offers an alternative to criterial features in defining categories. (shrink)

This volume contains a selection of contributions to the workshop 'Linguistic realization of evidentiality in European languages', held at the 30th Annual ...

Les constructions et la sémantique de trois verbes anglais sont analysées dans cette étude. Une distinction est établie entre appear et seem d’un côté, et look de l’autre. D’un point de vue cognitif, les premiers se rapportent à l’idée de perception, c’est-à-dire de visibilité orientée vers le sujet, alors que le second se rattache à ce que j’appelle les « apparences construites », c’est-à-dire, observation orientée vers la cible. Ces verbes représentent ainsi deux type différents d’intégration conceptuelle.