What does it mean to explain language change? Usage-based perspectives on causal and intentional approaches to linguistic diachrony, or: On S- curves, invisible hands, and speaker creativity

Abstract

The question how language change should be explained has been intensely debated in linguistic research, and causal and intentional – or in Coseriu’s terms, final – approaches have been proposed as the two basic options that are possible here (cf. Coseriu 1958). I will therefore start by critically reviewing the legitimacy and potential of conceiving language change in causal terms. In a next step I will turn to intentional explanations, which have been proposed as the second fundamental type of approach, and then investigate whether the controversy about causal vs. intentional explanations of language change can be resolved by assuming different mechanisms and types of explanation for the stages of innovation and propagation respectively, as proposed by Keller and Croft. In these reflections key assumptions of Cognitive Linguistics, more specifically of usage-based approaches to language and language change (Barlow/Kemmer 2000), will serve as a constant guideline, as they provide helpful criteria to judge the adequacy of explanations that have been previously proposed. Finally I will discuss the perspectives offered by usage-based approaches for explaining language change by outlining fundamental motors of change as well as their interplay in cognition and communication.