Reviewed by: Motives for language change Marc Pierce Raymond Hickey , ed. Motives for language change. Cambridge: Cambridge University Press. 2003. Pp. ix + 286. US$65.00 (hardcover). This book, a Festschrift in honour of Roger Lass, contains 15 papers covering a wide range of subjects, from the role of the speaker in language change to processes in new dialect formation. The book is divided into six sections, and there is also a brief introduction by the editor, which offers a brief historiographical perspective on the study of language change and describes the contents of the book, as well as an index. The first section, "The phenomenon of language change", consists of two papers. In "On change in 'E-language' ", Peter Matthews raises a number of questions regarding the Chomskyan distinction between "I-language" and "E-language" (roughly, the idiolect and "external linguistic production", to borrow a definition from Lightfoot 1999:66) and [End Page 72] the modelling of change in its terms. Frederick New meyer then turns to an old and still-difficult problem, in his "Formal and functional motivations for language change". Issues discussed here include whether a formal account of language change really "explains" anything, and the sometimes rather loose links between a functional explanation and the data it is meant to account for. The second section, "Linguistic models and language change", contains four papers. In "Metaphors, models and language change", Jean Aitchison concentrates on the use of metaphors in shaping the study of language change (cf. Lass 1997). She seeks to understand why particular metaphors associated with language change have arisen and whether such metaphors (e.g., trees, waves/ripples, games, buildings) have "helped or hindered our understanding of language" (p. 40). David Denison's "Log(ist)ic and simplistic S-curves" discusses the use of S-curves in historical linguistics; his arguments are illustrated with data drawn from the history of English. The title of Richard Hogg's paper, "Regular suppletion", seems to be an oxymoron, as suppletion is normally assumed to be irregular by definition. Hogg argues that suppletion can sometimes in fact be regular, or even cause regularity, and supports his claims with examples like English went, where suppletion has won out over regularity, and English be, where suppletion has led to "the creation of a new regular inflection" (p. 80). The final paper in this section, "On not explaining language change: Optimality Theory and the Great Vowel Shift", by April McMahon, is another in a series of works by McMahon critically examining the use of Optimality Theory in the study of language change (e.g., McMahon 2000). McMahon rejects the use of constraint reranking to model language change (the only such formal device available to OT, given that all constraints are universal), calling it "descriptive at best, fortuitous at worst, and post hoc either way" (p. 93). Section III, "Grammaticalisation", opens with David Lightfoot's "Grammaticalisation: Cause or effect". The status of grammaticalisation remains controversial; while some historical linguists appear happy to rely on its principles in their analyses, others categorically reject grammaticalisation as an explanatory principle (cf. Haspelmath 1999, Janda 2001, and Joseph 2001 for some relevant discussion). Lightfoot reviews a number of changes to the modal auxiliary verbs in English, but proposes "local causes" for them, instead of "invoking any general tendency to grammaticalise as an explanatory force" (p. 107). The next paper, "From subjectification to intersubjectification", is by one of the most prominent scholars of grammaticalisation, Elizabeth Closs Traugott (cf. Hopper and Traugott 2003). Here Traugott argues persuasively that there is a unidirectional tendency for intersubjectification to develop from subjectification, and supports this claim with evidence from the history of English. The fourth section, "The social context for language change", consists of one paper, "On the role of the speaker in language change", by James Milroy. Milroy discusses both internal and external factors in language change, and then examines certain developments in African-American Vernacular English as spoken in Detroit which, in his view, can only be adequately accounted for by reference to social factors. Section V, "Contact-based explanations", contains four papers, beginning with "The quest for the most 'parsimonious' explanations: Endogeny vs. contact revisted", by Markku Filppula. Filppula...