The purpose of this volume is to make easily available a representative selection of Charles-James N. Bailey's views on linguistic theory. Several previously published papers have been extensively revised and updated for the collection, which also contains two new chapters. The collection is flanked by a new Prologue and Epilogue, and the whole is preceded by Peter Mühlhäusler's Introduction which offers a critical appraisal of Professor Bailey's contribution to the field. In the Prologue the author discusses the rationale for a Developmentalist, or time-based, framework for the scientific analysis of languages; in the Epilogue he laborates a new approach to historical linguistics. These initial and final chapters reflect the volume's twofold emphasis on time-based analysis both in descriptive (multi-dialectal) analyses of languages and in historical analysis. For historical analysis Professor Bailey contrasts his approach with the current paradoxical practice of employing static models that exclude a time parameter - an approach which he characterizes as 'synchronic-idiolectal'. In doing so he offers explanations for matters which have not previously been accounted for in a satisfactory way: why and when languages change, the disruptive effects of language contact in triggering important kinds of change and the role of markedness in complex changes. Concentrating on the sound system and syntax of English, he presents a time-based model with rules for generating highly complex, multiphased phenomena which have been, until now, impervious to linguistic analysis.