This is a basic reader in 19th century European political thought. While there are selections from the 18th and 20th centuries, they occupy about 1/4 of this 465 page volume. For the most part readers will be learning what 19th century Europeans thought about politics - the revolutionary and post-ww1 eras receive very short treatment.
While the gloss of 18th century political thought is partially made up for by the earlier volume, the dearth of material from the post-ww1 era is difficult to explain. There was not, as the editor suggests, any dearth of big political ideas in the 20th century. Anti-imperialism, fundamentalism, and gender politics have all come to the fore in the 20th and 21st centuries, and influenced huge numbers of people. Personally I would have included Fukuyama, Junger, Keynes, Burnham, Gandhi, Mao, etc. Limited space of course poses some limits, but I wouldn't have excluded any of those authors in order to make room for Harold Laski. Or Adolf Hitler, for that matter, who was certainly no great original theorist.
Even if we were going to restrict the period to the "long 19th century" (1789-1914), there was still plenty of ground left uncovered. What is the Third Estate? and The Declaration of the Rights of Man and the Citizen were both crucial political documents of the revolutionary era. I would have also included Dostoyevsky in any discussion of Conservatism - more than almost any other author, he warned about the dangers of mass politics in a secular age. One also misses a discussion of Imperialism, about which a great deal was written by Europeans in the 19th century (Kipling, Cromer, Conrad.) Race-thinking and eugenics probably also deserved a place. The subjects are distasteful, but there's no doubt they influenced a large number of people.
Moving forward a bit, it's difficult to understand why we have no discussion of Totalitarianism and the Holocaust. Hannah Arendt had some interesting things to say about both. Hitler himself might not have been any great political thinker, but he had to get his ideas from somewhere. What about a speech from Mussolini, or an extract from Spengler or Huston Stewart Chamberlain? Why not include some of Hannah Arendt's reporting on the trial of Adolf Eichmann? The last is a particularly famous political document in the 20th century. "The Banality of Evil" might not be a "big theory" in the sense that conservatism or liberalism is, but it certainly explains a lot about what's been going on in the world over the last century. Anyone who is at all interested in politics should probably also read Orwell's essay "politics and the english language," which demonstrates the mechanics of political double talk and hypocrisy faster and more thoroughly than just about any other work on the topic. I can think of about a dozen authors who made it in, whom I would have gladly kept out in order to include a few excerpts from that essay.
Criticism aside, the works that did make it in are for the most part both valuable and interesting. Readers who already have a basic understanding of the subject will be familiar with Burk, Mill, Tocqueville, and Marx, but those who are just being introduced to it will get a chance to sample the writing of some of the most important political thinkers in European history. A little further off the beaten path, I also enjoyed the selections from Rawles, Bernstein, Saint-Simon, Sorel, Weber, and Niebuhr.
Unfortunately reviews that are long on criticism and short on praise invariably leave the impression that "this is a bad book." In this case that's not really true. I did enjoy this book, and I do think it's worth the price. It's just in the nature of things, I suppose, that when you like something there isn't much more you can say than "I liked it," but when you disagree with something, it's easy to think of two or three reasons why. In any case, I encountered some thinkers here for the first time, and was inspired to investigate further. This book isn't really a comprehensive selection of the crucial ideas in political philosophy, but it is nonetheless a good read.