Gary Saul Morson:

How did Dostoevsky anticipate what would happen? For one thing, he took the beliefs of intellectuals seriously. It is one thing to have ideas, it is quite another to define oneself and others by them (and that is what the Russian word intelligent — not exactly “intellectual” — suggests). Dostoevsky asked: what would people who defined themselves by ideology do if given the absolute power a revolution confers? Solzhenitsyn, who experienced the answer, asked a related question: why were previous evildoers, like those in Dickens and Shakespeare, content with a few murders whereas Bolsheviks executed millions? “The imagination and the spiritual strength of Shakespeare’s evildoers stopped short at a dozen corpses,” Solzhenitsyn explains, “because they had no ideology. Ideology — that is what … gives the evildoer the necessary steadfastness and determination.” The sort of ideology Dostoevsky and Solzhenitsyn had in mind displays two essential attributes: absolute (“scientific”) certainty and the division of people into purely good and purely evil. One does not break bread with someone from another political party. Once one thinks this way — as ever more people do — literally anything is possible to those commanding sufficient power.