Raymond Aron

In his 1955 book, The Opium of the Intellectuals, Aron argues that in post-war France Marxism was the opium of intellectuals - a twist on Karl Marx's cliché that ‘religion is the opium of the people’. Aron chastised French intellectuals for what he described as their harsh criticism of capitalism and democracy and their simultaneous defense of Marxist oppression, atrocities and intolerance.

In the 'Forward to the Transaction Edition', Daniel J. Mahoney and Brian C. Anderson, comment "This text is Aron's magisterial response to the efforts by Jean-Paul Sartre and other French intellectuals to fuse Marxist historicism and existentialist commitment in a way that abandons any concern with political moderation and prudence.  In it Aron supplements and explains the intentions of 'The Opium of the Intellectuals, and makes clear that his own conservative-minded liberalism is not rooted in radical skepticism about principles per se but in a legitimate skepticism about 'schemes, models and utopias.' "

Critic Roger Kimball suggests that Opium is "a seminal book of the twentieth century."