这本书主要探讨群众运动的一些共有特征，重点是陷入狂热的乌合之众的人格。长期与下层民众打交道的生活经历使作者发现，积极投身群众运动的往往是一些失意者。他们认为自己的生活已无可救药地失败，渴望逃离自我寻求重生，将生命托付给某项神圣伟业让他们感觉不错，整齐划一的集体生活令个人的责任、恐惧、无能得以掩埋。运动的领导者则刻意培养参与者的罪恶感，号召自我牺牲以获救赎。
自1951年出版后，《狂热分子》即被视为社会科学领域的经典之作，短期内行销50万册以上，被译成10余种语言，是多所大学政治系的必读书。书中俯拾皆是充满智慧的思想火花与一针见血的比喻，风格酷似法国思想家蒙田与帕斯卡尔的随笔。至今，其佳言警句仍不断被引用、辑录。

A fascinating, definitive, and very personal rumination on the history, science, philosophy, art, and literature of walking, by a skilled cultural commentator.
Geoff Nicholson, author of Bleeding London and Sex Collectors, turns his eye to the intellectual and cultural history of that most common of activities—walking. This simple, omnipresent activity has inspired numerous subcultures, literary and artistic legacies, sporting events, personal memories, epic journeys, mystical revelations, and scandals.
It’s a rich tradition that embraces such novelists as Charles Dickens and Paul Auster, musicians like Robert Johnson and Bob Dylan, and moviemakers from Buster Keaton to Werner Herzog. But it’s also a tradition that includes obsessives and eccentrics, such as the artist Mudman, who coats his body in mud and then walks the city streets; competitive pedestrians such as Captain Barclay, who walked one mile an hour for a thousand successive hours; and gang members who use the hidden language of the “Crip Walk” to spell out messages in the dirt with their scuffing. How we walk, where we walk, why we walk announces who and what we are.
Geoff Nicholson is a master chronicler of the hidden subversive twists on a seemingly normal activity. He analyzes the hows, wheres, and whys of walking through the ages. He finds people who walk only at night, or naked, or for thousands of miles at a time, in costume, for causes, or for no reason whatsoever. Here, he brings curiosity and genuine insight to a subject that often walks right past us.