‘This is an excellent book, actually the book, for the beginning graduate student who wants to keep up with the often confusing journal literature and the twists and turns of the intellectual debate. Now into a fourth edition, the “Scarth Express”, as we used to say circa 1975, is still going strong. This was a reference to the speed at which the material was delivered, in class, on a blackboard. No such problems for the reader of this volume.’