This chapter, by four authors, traces the rise, development, critique, and demise of a diversity of theoretical stances in philosophy and linguistic meaning from 1880-2000, e.g.,

• — modern logic, formal semantics, the linguistic turn in philosophy, truth-conditional semantics, intensional logic, possible world-semantics, categorial (Montague) grammar and ‘generalized quantifiers’;

• — logical positivism and its critiques, ‘analytic’ statements, ‘radical interpretation’, ‘truth-theoretical semantics’, ‘proof-theoretical semantics’;

• — psychological accounts of meaning, communitarian agreement; proper names as ‘rigid designators’; reference fixing vs. the properties of a ‘kind’ in all possible worlds;

• — the ‘cognitive’ era: meaning as a property of mental states (’concepts’), the philosophy of mind, the naturalization program, intentional generalizations with a computationalist view, ‘narrow’ and ‘broad’ concepts of meaning, and the functions of informational structures.

• — Speech Act Theory and pragmatics: ‘ordinary language philosophy’; performance in a context, felicity conditions, intentional and conventional aspects, communicative intentions, conventional meanings, the Cooperative principle, and inferences from conversational implicatures; presumption of rationality, ‘relevance theory’, combining pragmatics and a theory of mind; Discourse Analysis (Birmingham and Geneva School); enunciation theory; intersubjectivity; ‘polyphonic’ notion of subject, argumentative values, scales, and beliefs, Topoi Theory and the ‘theory of semantic blocks’.

Introduction

The first part of this paper examines the consequences of an interlocking set of mutualisms, involving ants, plants, bacteria and phloem-feeding insects, for the structure and functioning of herbivore-based food webs in tropical communities. This part draws heavily from important recent work by Davidson and colleagues (Davidson 1997; Davidson et al. 2003) and extends their discussion of community-level implications of their findings. The second part explores how trophic interactions evolve when coevolution produces specialized symbiotic ant–plant mutualisms, and is based largely on our own work on interactions between ants and Leonardoxa myrmecophytes of African rainforests. The paper complements a recent general review of ant–plant protection mutualisms (Heil & McKey 2003).

Ant–plant–herbivore interactions and tropical food webs

How food webs function, and how trophic interactions shape communities, have long been central questions in ecology. Interactions between organisms at adjacent trophic levels – predators and prey, parasites and hosts – and competitive interactions among organisms at the same trophic level, all occupy major roles in theories to explain the great species richness and other traits of tropical forest ecosystems (Wright 2002). Following the lead of classic studies like those of Hairston et al. (1960) and Paine (1966), investigations of how communities function have increasingly taken into account not only these direct interactions, but also indirect interactions that extend across several trophic levels. Do natural enemies of herbivores have measurable impacts on fitness of individual plants, on relative abundance of plant species, on primary productivity or on plant species diversity?