This book goes beyond the boundaries of a standard text, using controversial and compelling ideas to explore the relationship between fundamental concepts in historical linguistics.
This book is neither an introduction to historical linguistics nor a textbook for an advanced-level historical linguistics class. It does present an idiosyncratic and abstruse generative take on the problem of language change. The author writes fairly well, but he doesn't tackle anything particularly important. He also restricts himself to generative approaches, which gives a very skewed view of the field of historical linguistics (and has pretty big empirical problems, to put it mildly).