"The Crowd" is a book written by Gustave Le Bon in 1895 that explores the behavior of crowds and how individuals act differently when they are part of a group. Le Bon argues that crowds can lead to irrational behavior, as individuals often lose their sense of personal responsibility and are influenced by the emotions and actions of others. The book discusses the psychological mechanisms that drive crowd behavior, including the spread of ideas and emotions. Le Bon emphasizes that crowds can be powerful forces, capable of shaping public opinion and influencing social movements, making it essential to understand their dynamics.