Julien Benda's classic study of 1920s Europe resonates today. The "treason of the intellectuals" is a phrase that evokes much but is inherently ambiguous. The book bearing this title is well known but little understood. This edition is introduced by Roger Kimball.

From the time of the pre-Socratics, intellectuals were a breed apart. They were non-materialistic knowledge-seekers who believed in a universal humanism and represented a cornerstone of civilized society. According to Benda, this all began to change in the early twentieth century. In Europe in the 1920s, intellectuals...