These sections are rather overweight where the account of minor varieties of socialism is concerned (though, curiously, Trotskyism and Maoism get no proper treatment), and a rather defensive tone creeps in whenever Marxism is looked at from the viewpoint of 20th-century history. Here one feels that Alan Ryan shows himself to be a child of his time, the time in question being when he was a young man and the thinking of the early Marx was being rediscovered by Western intellectuals as a humanistic quest for freedom and self-expression. To Lenin's claim that "because Marxism was a science, there was no more room for freedom of speech in Marxism than in chemistry", he responds that "there is a great deal of freedom in chemistry and scientific theories are not protected from criticism by putting a bullet in the back of dissenters' heads". 

What Ryan says is true, but the implied defence of Marxism (absolving it of any responsibility for the Lenin-style treatment of opponents) seems questionable to me. Marxism claims to be not just a science about physical things (as chemistry is) but a science that explains people's beliefs and values — at least, the beliefs and values of non-Marxists. Once you know "scientifically" that other people's objections to your rule are expressions of false consciousness arising from hostile economic interests that must inevitably be swept away by history, doesn't that make you a little more likely either to deny them freedom of speech, or to grant them a bullet in the back of the head?

This is one of the rare moments in the book where I feel that Alan Ryan might be accused of being imperceptive. There may be other passages that other readers will disagree with, for reasons that are political, or historical, or both. But never mind — this is a colossal and deeply engrossing work, by someone who is simply incapable of writing a dull or an unintelligent page.