Conceptual spaces are a frequently applied framework for representing concepts. One of its central aims is to find criteria for what makes a concept natural. A prominent demand is that natural concepts cover convex regions in conceptual spaces. The first aim of this paper is to analyse the convexity thesis and the arguments that have been advanced in its favour or against it. Based on this, I argue that most supporting arguments focus on single-domain concepts (e.g., colours, smells, shapes). Unfortunately, (...) these concepts are not the primary examples of natural concepts. Building on this observation, the second aim of the paper is to develop criteria for natural multi-domain concepts. The representation of such concepts has two main aspects: features that are associated with the concept and the probabilistic correlation pattern which the concept captures. Conceptual spaces, together with probabilistic considerations, provide a helpful framework to approach these aspects. With respect to feature representation, the existence of characteristic features (i.e., that apples have a specific taste) is essential. Moreover, natural concepts capture peaks of a probabilistic distribution over complex spaces. They carve up nature at its joints, that is, at areas with no or low probabilistic density. This last aspect is shown to be closely related to the convexity demand. (shrink)

Syntactic semantics is a holistic, conceptual-role-semantic theory of how computers can think. But Fodor and Lepore have mounted a sustained attack on holistic semantic theories. However, their major problem with holism (that, if holism is true, then no two people can understand each other) can be fixed by means of negotiating meanings. Syntactic semantics and Fodor and Lepore’s objections to holism are outlined; the nature of communication, miscommunication, and negotiation is discussed; Bruner’s ideas about the negotiation of meaning are explored; (...) and some observations on a problem for knowledge representation in AI raised by Winston are presented. (shrink)

I argue that analyses of various kinds of cooperation will benefit from an account of the cognitive and communicative functions required for the cooperation. In particular, I focus on the role of intersubjectivity , which has not been sufficiently considered in game theory. Intersubjectivity will here be divided into representing the emotions, desires, attention, intentions, and beliefs of others. I then analyze some kinds of cooperation—reciprocal altruism, indirect reciprocity, cooperation on future goals, and conventions—with respect to their cognitive and communicative (...) prerequisites. It is argued that uniquely human forms of cooperation depend on advanced forms of intersubjectivity. (shrink)

This paper discusses how we understand and use a concept or the meaningof a general term to identify the objects falling under the term. There aretwo distinct approaches to research on the problems of concepts and meaningthe psychological approach and the formal (or logical) approach. My majorconcern is to consider the possibility of reconciling these two differentapproaches, and for this I propose to build a psychologically plausibleformal system of conceptualization. That is, I will develop a theory-basedaccount of concepts and propose (...) an explanation of how an agent activates aperspective (which consists of theories) in response to a situation in whichreasoning using a concept is called for. Theories are represented as sets offacts and rules, both strict and defeasible. Each theory is organized in acoherent perspective which stands for an agent's mental state or an agent'smodel of another agent's perspective. Perspectives are organized intohierarchies and the theory for a concept in one perspective may defeat thetheory for the same concept in another perspective. Which perspective issuperior is context-dependent. (shrink)

In spite of contemporary theoretical disagreement on the nature of language, there is a widespread informal agreement about what linguistic facts are. This article argues that a functional approach to language can provide the foundation for an explicit account of what the informal consensus implies. The account bridges the ‘internalist’ and the ‘externalist’ views of language by understanding mental constructs such as those involved in human languages as aspects of a dynamic social equilibrium. As in evolutionary biology, processes of selection (...) can work to stabilize certain features while others vary; and this process (in which ‘function’ plays a key role) is a necessary supplement to a purely mentalist account. This position is seen as a development of the position of Searle on social facts and Keller on language change. (shrink)

The meanings of words are not permanent but change over time. Some changes of meaning are quick, such as when a pronoun changes its reference; some are slower, as when two speakers find out that they are using the same word in different senses; and some are very slow, such as when the meaning of a word changes over historical time. A theory of semantics should account for these different time scales. In order to describe these different types of meaning (...) changes, I present an analysis of three levels of communication: instruction, coordination of common ground and coordination of meaning. My first aim is to show that these levels must be considered when discussing lexical semantics. A second aim is to use the levels to identify the communicative roles of some of the main word classes, in particular nouns, adjectives, verbs, indexicals and quantifiers. I argue that the existence of word classes can, to a large extent, be explained by the communicative needs that arise on the different levels. (shrink)

This dissertation is a contribution to the philosophy of language. Its central question is: In virtue of which facts do linguistic expressions mean what they do? E.g. why does “apple” mean apple in English? The question receives a systematic answer; in short: Linguistic expressions mean what they do because among their users, there are linguistic conventions and social norms to use and understand them in certain ways. The answer is clarified and defended as a central thesis. For in this form, (...) it is at best a slogan: What is meaning? What is it to use and understand expressions? What are conventions and social norms anyway? How does the use and understanding determine meaning? The goal of the dissertation consists in answering these questions. (shrink)

This thesis studies the role of conceptual content in inference and reasoning. The first two chapters offer a theoretical and historical overview of the relation between inference and meaning in philosophy and psychology. In particular, a critical analysis of the formality thesis, i.e., the idea that rational inference is a rule-based and topic-neutral mechanism, is advanced. The origins of this idea in logic and its influence in philosophy and cognitive psychology are discussed. Chapter 3 consists of an analysis of the (...) relationship between inference and representation. It is argued that inference has to be studied from a pluralistic per- spective due to its dependence on different formats of representing information. The following four chapters apply conceptual spaces, a formal theory of concepts within cognitive semantics, to three concept-based inference-types. First, an explication of Sellars notion of material inference is advanced. Later, the model is extended to account for nonmonotonic inference by studying the role expectations in reasoning. Finally, a conceptual space-model of category-based induction is presented. This model predicts most of the empirical properties of this psychological phenomenon and subsumes some of the previous theories in psychology. It is stated that the explanatory fruitfulness of this new approach is evidence for the failure of the formality thesis and calls for a unified model of rational inference that puts semantics at center stage. The last chapter of the thesis discusses how inference and concepts interact in scientific reasoning, which makes constant use of hybrid symbolic structures for representing conceptual information. Stephen Toulmin’s notions of method of representation and inferential technique are developed and applied in a case study about the emergence of the notion of instantaneous speed during the passage from geometrical physics to analytical mechanics. It is claimed that this analysis provides support to the pluralistic perspective for theorizing about reasoning. (shrink)

This paper1 explores, quite tentatively, possible consequences for the concept of semantics of two phenomena concerning meaning and interpretation, viz., radical interpretation and normativity of meaning. Both, it will be argued, challenge the way in which meaning is conceived of in semantics and thereby the status of the discipline itself. For several reasons it seems opportune to explore these issues. If one reviews the developments in semantics over the past two decades, one observes that quite a bit has changed, and (...) one may well wonder how to assess these changes. This relates directly to the status of semantics. If semantics is an empirical discipline, one might expect that most changes are informed by empirical considerations. However, one may also note that the core notion of semantics, meaning, today is conceived of quite differently than in, say, the seventies. How can that be? How can that what semantics is about, be different now from what is was back then? Or is this perhaps an indication that semantics is not as empirical as it is often thought to be? Moreover, it seems that in some deep sense meaning as explicated in semantics and interpretation as studied in various philosophical approaches are strangely at odds. Meaning is what interpretation is concerned with: meaning is, at least so it seems, what in the process of interpretation language users try to recover (or analogously, what they try to convey in production). Yet, the way meaning is conceived of in semantics seems not to square all that neatly with how the process of interpretation is supposed to proceed. In particular it seems to lack some of the intrinsic features that various approaches to interpretation assume it to have. Given these discrepancies, one wonders how the two can be incorporated within a single theory. And that such a theory is desirable goes, it may be presumed, without saying These are the reasons that figure in this paper. At the background there are some others.. (shrink)