Based on wonderful books like Jonathan Culler's "Very Short Introduction to Literary Theory," I had come to expect more from the series. This book is poorly written, full of muddy, half-developed thought, and even contains several typos.
The book is organized as a more or less chronological presentation of major schools of legal philosophy (from natural law and positivism through critical legal studies), with the major thinkers in each school usually receiving their own brief sections. Unfortunately, these sections tend to consist largely of scattershot presentations of various doctrines asserted by the thinker. Little attempt is made to string the doctrines together into developed thoughts, or to suggest what problem the thinker hoped to solve by setting forth his or her doctrines, much less to locate the doctrines in a larger intellectual history.
I found that if I was already familiar with the thinker being discussed, the book's presentation often contained subtly misleading phrasing; and if I was not familiar with the thinker, I came away still unclear about why the thinker had bothered to assert the various, vague statements about the law that had been summarily presented. One premise of the Very Short Introduction books is that it's not impossible to say something worthwhile about the significance of a philosopher's contribution to legal theory in even a single paragraph. But doing so requires work. It requires synthesizing the philosopher's claims and locating them in some context, not just throwing out a few vaguely connected, undeveloped doctrines. Those interested in getting a first impression of the philosophy of law would be better off visiting the Wikipedia pages of a few legal philosophers than buying this book.
This is the kind of book that offers a passage like the following -- "Raz actually postulates a stronger version of the 'social thesis' (the 'sources thesis') as the essence of legal positivism" -- and then fails to define the "sources thesis." The thesis is evidently important enough to be mentioned three times in two pages, but is never defined.
If you're like me, and you like your theses to be stated, you might find this book frustrating.
Another characteristically frustrating passage: "Since Kelsen argues that the effectiveness of the whole legal order is a necessary condition of its validity of every norm within it,..." I can't even tell what went wrong in that sentence: is it a typo? Bad grammar? Unclear thought?
(For more straightforward typos or grammar errors, see p. 37 ["by reference to three elements; efficacy, institutional character, and sources"], p. 55 ["Can I not have a duty without you (or anyone else) having a right that I should perform it."], etc.)
The author also offers gratuitous, unsupported praise or scorn for various thinkers, such as the following throwaway remark about Critical Legal Studies: "Yet the possibilities of transforming the law seem frequently to be diluted by the destructive, even nihilistic, tendencies of some of the more dogmatic adherents of CLS." Really? Thanks for the tip! (No identification of these adherents is offered, nor any clarification of the sense in which they are "nihilistic," nor any clarification of how their nihilism might dilute the possibility of transforming law.)
Finally, the book contains a glaring omission that is apparently typical of philosophers of law who were trained in England. It makes no mention of the thought of (the German) Friedrich Carl von Savigny, and instead presents many of Savigny's central ideas as though they were invented by (the English) John Austin, who in fact got the ideas directly from Savigny.