I enjoyed this no end. A concise, well-organised, beautifully clear-headed book. Porter Abbott is generous to every idea and, in caring about them, he does them justice. Here is an author who evidently loves his subject - and this is infectious. But he does not preach, he simply opens up the subject and encourages further curiosity. Above all, the book makes you thirst again for the primary texts with the feeling that, the next time you read, the experience will be richer for what you now know. All introductions to a subject should be like this.