Levels of communication and lexical semantics

Abstract:
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, and indexicals. 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. 

About Peter Gärdenfors:
Peter Gärdenfors e is known for his groundbreaking work on belief revision and belief dynamics (viz. the AGM framework, coauthored with Carlos Alchourron and David Makinson) and for his decisive contributions to the theory of conceptual representations. In 2000, Peter Gärdenfors published "Conceptual Spaces: The Geometry of Thought", MIT Press, 2000. He just published "The Geometry of Meaning: Semantics based on Conceptual Spaces" (MIT Press, 2014), which pursues his program of naturalizing the theory of meaning.